BaK4 vs BK7 prisms

I was shopping for binoculars recently, and in the process of researching what to buy I saw a big fuss about BaK4 (barium crown glass) prisms. The Internet made many vague claims of "sharper" and "expensive therefore better" in comparing BaK4 to BK7 (borosilicate crown glass), but what is really happening?

Joshua Tree

Yesterday we rented some equipment (tent, sleeping bags, mats, cookstove) from the Caltech Y, packed everything into the car and drove out to Joshua Tree. 

Binoculars

Bought a pair of Celestron 8x42 binoculars last weekend ($64, Woodland Hills Telescope). The pictures make them look smaller than they actually are; remember that the objective lenses are 42mm in diameter. The width feels pretty nice, but they are a bit longer than I'd like.

The good

Parrots!

Red-masked parakeets, actually. I'd seen them at this same location the first day after I moved in to Caltech and have been on the lookout for them ever since.

Telescope

I bought a telescope yesterday! It is a Meade 70AZ-A, a 70mm refractor with a 600mm focal length (f/8.5). I got it for $70 from Woodland Hills Telescope (the brick-and-mortar version). They were pretty busy when I was there, but they're nice and have a good camera/photo department as well.

Big Nikon lens and camera review

I've been taking pictures for almost a year now. I wouldn't describe myself as a photographer..more like a camera enthusiast.

I started with a Nikon N65 and a normal zoom lens that my dad had bought me new in 2001. Over the last 10 months, I've been doing a lot of eBay shopping and have now accumulated 9 lenses and 5 camera bodies:

Lenses:

1. 28-80mm f/3.5-5.6 AF-D
2. 50mm f/1.8 AF
3. 70-210mm f/4-5.6 AF
4. 200mm f/4 AI
5. 180mm f/2.8 AF
6. 180mm f/2.8 AI
7. TC-200 2x teleconverter
8. 24mm f/2.8 AI
9. 20mm f/4 AI

Camera bodies:

1. N65
2. FE

Here are my thoughts on this collection of photography equipment:

LaTeX: getting back in the saddle

After spending more than a year away from LaTeX, I have forgotten so much. Here are the things I've had to look up so far:

Setting up LaTeX

I'm using a Mac now and TeXShop. Fortunately it comes with a template, which I've modified slightly (to use the "article" document class). I also installed cocoAspell, which is a dictionary that will filter out the LaTeX keywords. After installation, you have to go to its section in System Preferences to enable the dictionaries and turn on the LaTeX filter. You could go to either System Preferences -> Language & Text or TexShop's Edit->Show Spelling and Grammar (or both) to set it to use the Aspell dictionary.

LaTeX commands

To change the section and subsection numbering style:
\def\thesection {\arabic{section}.}
\def\thesubsection {(\thesection\alph{subsection})}

Set of all reals:
\usepackage{amssymb}
\mathbb{R}

Indicator function:
\usepackage{bbm}
\mathbbm{1}

Lots of symbols:
http://www.artofproblemsolving.com/Wiki/index.php/LaTeX:Symbols

Aligned equations:
\usepackage{amsmath}
\begin{align*}
g^{-1}(\xi) &= \{x \in \mathbb{R}: g(x) = \xi\} \\
h^{-1}(\psi) &= \{y \in \mathbb{R}: h(y) = \psi\}
\end{align*}
If you're trying to align a single equation in multiple places. The parameter is # of columns, which is (# of & signs + 1)/2. Every other & is for alignment, the other ones specify where to add the whitespace.
\begin{alignat*}{2}
f &= ax + b && \ge 0 \\
h &= cx && = 0 
\end{alignat*}

Defining a piecewise function, with the big curly bracket:
f_{Z|X}(z,x) = f_{Y}(z-x) = \begin{cases}
\frac{\mu^{z-x}}{(z-x)!} e^{-\mu} & z-x \ge 0 \\
0 & z-x < 0
\end{cases}

Keeping fractions big:
\frac{\displaystyle ...}{\displaystyle ...}

Particular spacing:
\int x\,dt
i.e.\ in other words

Command shortcuts:
\newcommand{\norm}[1]{\lVert#1\rVert}
\newcommand{\reals}{\ensuremath{\mathbb{R}}}
\def \ba#1\ea {\begin{align*}#1\end{align*}}

Tables:
http://en.wikibooks.org/wiki/LaTeX/Tables

Keeping functions together:
\relpenalty and \binoppenalty
http://www.guyrutenberg.com/2006/12/10/prevent-line-breaking-inline-formula-in-texlatex/

How to turn a Windows laptop into a wireless adapter

Background:

I have a desktop computer with an Ethernet port, a laptop with Ethernet and WiFi, and a house with an Internet connection on WiFi only.

Windows has a nice little utility call "Internet Connection Sharing" (ICS) that should let me plug my desktop into my laptop and use the laptop as a software gateway to connect the Ethernet network to the WiFI network. However, ICS wants to use 192.168.0.1 as the host IP address, which just so happens to be the same address that the house's wireless router is using. This is a problem.

It looks like there are some workarounds, but they either involve registry changes or sound like hacks (i.e. setting static IP addresses before/after initializing ICS to somehow disable the DHCP sever...), so I am using another utility called NAT32, which markets itself as a "Windows software router".

Installation

1. Download and install the evaluation version from www.nat32.com
2. Start NAT32. Enter "driver install" into the NAT32 command line to install the NDIS3PKT driver. Reboot.
3. Setup the Ethernet adapter with a static IP. Turn off all firewalls around it. Connect the desktop to the laptop (normal Ethernet cable is fine; no crossover cables needed for modern Ethernet adapters) and check that they can ping each other.
4. Start NAT32 again. A configuration window comes up. Select the WiFi interface as the Internet connection. Select the Ethernet as the Private connection. Accept all default configurations

And that's it! I'm posting this post from the desktop! It took like an hour to setup because of the whole firewall thing. I could turn off the Windows Firewall just around the Ethernet connection and keep it up around the WiFi connection, but with McAfee I ended up turning it off entirely because I couldn't figure out how to do it for one connection only.

Mono Lake and Bodie

Adventures in buying a new car

Background

For a variety of reasons, we decided that we needed another car. And without a whole lot of detailed analysis, we decided that it should be:

• Fuel efficient
• A hatchback, or at least have folding rear seats
• Comfortable to drive on the freeway
• Manual transmission
• Safe
• New

New cowfish

During the move, we discovered that one of the cowfishes (our name for our Panda Cories, which look and act like cows) had crossed over the fish tube without our noticing and died in the new tank.

Worried that our last remaining cowfish would get lonely, we went up to Ocean Aquarium in SF last Sunday to get him some friends - two more panda cories.

They seem to be getting along well. Despite the old cowfish being significantly larger than the new ones, they are herding together. They appear more active at night, when the aquarium lights are off. During they day, they mostly swim slowly around the plant growth, but at night we've seen them going up and down the sides of the glass. They're very cute together!

Moving (again!)

Notes from moving from McFarland to Palo Alto. We got kinda tight on time towards the end, but it worked out. No U-haul van like last time, but also no furniture.

Lessons learned:

1. The G20 has a surprisingly large cargo capacity. 
2. Removing the fish from the tank makes moving them (and the tank) a lot easier. 
3. We get cranky when tired. 
4. Moving takes a long time.

Here's our notes from the process:

Sock experiment

Following on the heels (pun totally intended) of the windshield wiper experiment (which, by the way, indicates no difference between the two brands), I have started a sock experiment. My old socks developed holes in the heels, so I bought new ones:

• 6 pairs of the more expensive Hanes Premium Cushion Low Cut (78% cotton, 20% polyester, 1% natural latex rubber, 1% other fiber)
• 10 pairs of the cheaper Jerzees (a Russell brand) Low Cut (84% cotton, 13% polyester, 1% other fiber). 

The Hanes socks are identifiable by the black "Hanes" lettering (my old socks have red lettering, and the Jerzees are blank.

To remove bias in usage patterns, I will FIFO my clean sock supply (so each sock is worn exactly once between washes) and will randomize them upon queuing. Now we'll see which ones wear out first.

Japan - Tokyo 1

6/27 - 6/29 (Tokyo)

China - Shanghai

6/26 - 6/27: Shanghai

China - Nanjing

6/24 - 6/25: Nanjing and Yangzhou (picture is Shanghai Hongqiao rail station, though)

China - Beijing 2

6/19 - 6/23: Adventures around Beijing

China - Lijiang 2

June 17: Lijiang - (Snow mountain and some towns)
June 18: Travel, mainly.

China - Lijiang 1

June 16: Lijiang (bus and horse rides)

China - Dali

June 15: Dali

China - Kunming 2

June 14: rock forest and tourist traps.

China - Kunming 1

June 13: Kunming city

China - Beijing 1

June 8: Flying ANA to Beijing
June 9-12: Beijing and my grandparents' house

Adventures in homemade pizza

Last winter (2009-2010) I came across a particularly...opinionated pizza recipe by Jeff Varasano. His "they're wrong; I'm right; do this" style is very similar to Ken Rockwell's, and I am gradually accumulating evidence suggesting I'm an absolute sucker for that kind of writing. So I made some pizzas.

I think I'd describe them as...unique.

This was before I'd figured out how to make bread, so I was very concerned about the crumb:

I had a problem with the dough getting soggy from the sauce/toppings and not baking properly.

But if baked for longer, the dough dries out and develops a very thick crust (in the "bread crust" rather than "pizza crust" usage):

And then I guess I lost interest, because that last picture is from January of 2010.

Last week, the farmer's market had some awesome tomatoes and so I decided to try again.

I used my bread recipe for the crust, and I think it turned out better this time. I'm still using a preheated baking pan instead of a pizza stone, but I have an electric oven now, which I think is better suited for pizza. The heat is drier (natural gas makes 40g H₂O per MJ), and I think the stronger radiative transfer results in selective heating of the black enameled baking pan. I baked at 500 for 5 min and then turned on the broiler for a few minutes to brown the top of the crust.

For one pizza, I tried using a 1/8" thick sheet of aluminum 6061 instead of the baking pan, but I don't think that worked out as well. I also got a pretty weird smell from whatever cutting fluid residues were left on the metal. I wonder if it's still T6 anymore...

Anyways, to address the sogginess, I seeded the tomato before crushing it and used it very sparingly. It still got soggy, but it feels more like the dough got wet after cooking rather then being too wet at the beginning and refusing to cook properly.

The big revelation, however, was in the mozzarella. This time I used "Precious" brand fresh mozzarella from Mollie Stone's, and it tastes far better than any other mozzarella I've bought before (both fresh and low-moisture). Pretty awesome. Does release a lot of moisture, though - in the second picture, I put the cheese on 5 minutes into baking thinking it'd keep the moisture locked in the cheese, but this just succeeded in creating a layer of water over the pizza that didn't get a chance to evaporate before I pulled it out.

In conclusion: maybe I got better at making the crust, or maybe it's just the electric oven. Pizza is still soggy in some places, but the cheese and sauce taste awesome so it's okay.

USPS hold mail fail!

We held our mail for our China trip. Regular mail delivery resumed as scheduled (June 29), but our held mail didn't get delivered until today! Lame!

Removing Solidworks feature references

Let's say you had a feature, Shell1, at the beginning of your feature tree, and it is the feature that generates the solid body used by the rest of your feature tree.

Then you go and decide you want to use a Thicken (or something) instead of that Shell1. And then Shell1 breaks.

Now you're left with a ton of sketch and feature references back to the original Shell1. You manually reattach your sketch references to the new solid body, but you find that your features still reference Shell1. And if you delete Shell1, these features will also disappear. How do you update them?

If you create another, separate solid body (so now you have more than 1 solid body in your model), this activates the "Feature Scope" options in the feature, and now if you Edit Feature, you can select Thicken1 and the features will stop referencing the now-defunct Shell1.

Accessing the Words With Friends dictionary

Some Internet browsing led me to this procedure; just wanted to post it so I will remember. To get the dictionary file used by Words With Friends:

1. Copy the Words With Friends app file "Words.ipa" from the iTunes Mobile Applications folder (~\Music\iTunes\iTunes Media\Mobile Applications).
2. Rename the .ipa to .zip and open it
3. Get "enable1.txt" from Words.zip\Payload\WordsWithFriendsPaid.app

And that's the dictionary (I'm told ENABLE stands for Enhanced North American Benchmark Lexicon).

Mega image comparison

Using the same subject (some flowers...I'd call them daffodils, but they're purple), we have 3 sets of comparisons to make. In the first bout, our contenders are:

1. Snapfish scan
2. ScanCafe scan

In the second bout:

1. DIY scan (Epson Perfection V300, I think)
2. Swan photo labs scan
3. ScanCafe scan

Finally, the headliner matchup:

1. iPhone 4
2. Nikon D90
3. Print film (Fujicolor 100)
4. Slide film (Fujichrome Velvia 50)

Onto the comparisons!

Snapfish vs. ScanCafe

Here we have a print film scanned by two different vendors:

• Snapfish is primarily a digital photo products company, but they also run a mail-in photo processing and scanning service. They are very cheap (around $0.20 per image developed and scanned).
• ScanCafe is a photo scanning company in Bangalore that prides itself on high resolution scans "by hand". Their standard price is $0.35 per image, but often have sales. The biggest downside is their turnaround time - about two months.

Fujicolor 100, scanned by Snapfish

Fujicolor 100, scanned by ScanCafe

ScanCafe messed up on this one. I like the color and exposure on the Snapfish scan a lot better. This is generally not the case.

Fujicolor 100, scanned by Snapfish

Fujicolor 100, scanned by ScanCafe

In the details, it's not much of a fight. ScanCafe has better scanners and higher-res files.

DIY vs. Swan Labs vs. ScanCafe

Here we have a slide film scanned three ways:

1. By me, on an Epson Perfection V300 scanner using the provided software. Free, but fairly time-consuming (90 sec per image, or 50 min for a 36-exposure roll). 
2. Swan Labs, where my local camera store outsources their E-6 process. $0.18 to $0.39 per scanned image, depending on resolution (the examples below are the expensive kind).
3. ScanCafe (see first section) 

Fujichrome Velvia 50, scanned at home

Fujichrome Velvia 50, scanned by Swan Labs

Fujichrome Velvia 50, scanned by ScanCafe

These are remarkably similar. I think Swan Labs vs. ScanCafe is mainly an issue of taste regarding exposure settings. Even the DIY scan has similar color. A little hazy, but I think that can be fixed by the levels slider.

Fujichrome Velvia 50, scanned at home

Fujichrome Velvia 50, scanned by Swan Labs

Fujichrome Velvia 50, scanned by ScanCafe

The DIY scan is actually at a higher resolution (4000 dpi) than either of the outsourced scans, so the fuzziness is entirely due to the optics. The Swan Labs scan is supposed to be about the same resolution as the one by ScanCafe, but it has some very apparent blockiness. Fraudulent resizing? Bad Bayer algorithm?

Anyways, it's clear that ScanCafe sets the bar for scan detail. I like its colors, too.

iPhone vs. DSLR vs. negatives vs. slides

Four contenders in the final matchup:

1. iPhone 4 camera. Ubiquitous (for me, anyways) and quite good. $600 MSRP, but the camera is only a small portion of that.
2. Nikon D90 digital SLR. $780 MSRP.
3. Fujicolor 100 negative (print) film. $0.23 for film, processing, and low-res scanning. Add $0.30 for high-res scans.
4. Fujichrome Velvia 50 slide film. $0.65 for film, processing, and low-res scanning. Add $0.17 for high-res scans.

iPhone 4

Nikon D90

Fujicolor 100, scanned by Snapfish

Fujichrome Velvia 50, scanned by ScanCafe

Perhaps purple is not a good color for the iPhone sensor. I've gotten some great colors from the iPhone camera; this isn't. Comparing the darker corners of the image with the center, there's a clear color shift as one of the color channel saturates.

Here, the DSLR has too much dynamic range. Instead of losing the background clutter in the shadows, we retain contrast. And the greens and purples are not as saturated as in film. In that regard, the Velvia is just ridiculous. For this image, though, that's a good thing. Come to think of it, it's probably a good thing for anything worth taking a picture of.

iPhone 4

Nikon D90

Fujicolor 100, scanned by ScanCafe

Fujichrome Velvia 50, scanned by ScanCafe

The iPhone's tiny sensor loses big time on the image detail front. It's at a disadvantage on resolution (approx 2000 dpi vs. 3000 for the other images), but it's already struggling to fill those pixels with meaningful information. I think there's some clear evidence of edge sharpening and noise reduction going on here.

The DSLR, despite the DX format, is incredibly sharp. Simply astounding. This close-up image is an 8.6X crop of the original image, and it still looks fine. That's like getting a 300mm lens out of a 35mm lens. What.

The slide film beats out the print film in this contest. I don't know if that's supposed to happen, but the edges are a lot cleaner on the slide film. Hard to rule out focus issues or camera motion, however. The slide film is also a bit grainier, but it's not unpleasant.

Fish Tube

After talking about it for a long time, we finally implemented the fish tube: a fish-sized tube connecting our two 10-gallon aquaria.

February: We add gravel and plants to set up our second tank.

March-April: Many water tests on the new tank to ensure it's stabilized. One treatment of erythromycin in response to a blue-green algae bloom.

April-May: More water tests.

Date	Tank	NH4	NO3	PO4	pH	GH	KH	Notes
4/30	Old	0	5	0.5	7.6	5
	New	0	5	0.5	7.6	4		20% water change, started erythromycin
	Tap water				7.6	3
5/1	New							Nitrogen fertilizer, erythromycin
5/2	New							20% water change, erythromycin
5/3	New							erythromycin
5/4	New	0	10	2	7.2	5	4	20% water change, added nitrogen
5/7	New	0	5	1	7.6			20% water change, added nitrogen
5/11	Old	0	5	0.25	7.6	4
	New	0.25	5	0.5	7.6	5
5/19								Fish tube, 25% water change
5/22	New	0	5	0.25	7.6	5	4	Two tanks hopefully equilibrated

The Fish Tube

The fish tube is a clear rectangular tube, 1.75" x 2.25" in cross section (inside dimensions), constructed of acrylic held together with Loctite 3321 UV adhesive. It is shaped like an inverted U with a total length of 15" (measured along the center line).

It bridges the two tanks and provides a path through which our fish can swim from one to the other. Unfortunately, this is the furthest into the tube that the fish have ventured so far:

I also hoped the tube would allow stuff to diffuse between the two tanks. I tried to verify this using some quick calculations:

Using a published diffusion rate of 1.8×10^-9 m²/s for ammonium at 25°C and approximating the fish tube as 0.38 m long, Fick's law gives us J = -(4.7×10^-9 m/s)Δφ, where J is the diffusion flux (mol/m²s, say) and Δφ is the concentration difference (mol/m³). The tube has a 2.5 × 10^-3 m² cross-sectional area and each tank holds 40 L, which gives us dφ/dt = (0.063 m^-1)J for each tank, ultimately yielding:

dΔφ/dt = -(5.9×10^-10 s^-1)Δφ

which has a time constant of 54 years. Looks like molecular diffusion is not a significant factor. So we have to rely on macroscopic mixing due to flow within the tube, which I'm not able to characterize so easily. But I think it's probably happening!

Update (May 24): One rasbora in the new tank! He must have...gotten lost or something. But perhaps they'll start getting used to inter-aquarium travel!

Update (May 26): We decided the rasbora in the new tank looked pretty miserable being by himself, and probably wasn't there of his own volition. We chased him into the mouth of the tube using a net, but he was very reluctant to go further up the tube (i.e., above the water line). We started pushing the net into the tube, which finally encouraged him to get over his fears and enter the tube. He looked very confused, then swam quickly across the tube and back down into the old tank.

Update (June 5): Getting ready for our China trip. Stuffed some stem plants into the tube to prevent the fish from getting lost again. To keep the water chemistry more stable, I added a drain tube to siphon water from the new tank's filter into the old tank, creating circulation. A little worried because blue-green algae continues to be a problem in the new tank, but I am hoping that joining the two will provide the proper balance of nutrients to encourage plant rather than algae growth. Of course, it could go the other way, and we could come home to find both tanks overrun with cyanobacteria...

Update (July 23): Cyanobacteria still abounds in the new tank, though the old tank seems unaffected. I put snail into the new tank to eat the brown algae. He cleans it off very effectively, but he random-walks around the tank, so there are many areas left uncleaned.

The night before last, we found a rasbora sleeping in the fish tube! He was the slightly off-kilter one. We didn't know if figured out how the fish tube works or if he was just lost. In the morning, he was back in the old tank.

Last night, he was back in the tube! And later that night, he was sleeping in the new tank. This morning, though, he was pretty freaked out and trying to swim back to the old tank by running into the glass. I fed him, but he was too freaked out to eat. I chased him into the tube and had to push the net into the tube to get him to go above the water line. He's back in the old tank now.

Update (July 26): Yesterday the Oto made his way through the fish tube! He spent most of the day swimming frantically in the new tank. That night, he found his way back. At the same time, a rasbora (probably the same rasbora as before) spent the night in the tube and was in the new tank in the morning. He's still there.

Flat tire

Must have picked this up on the way back from Yosemite. Didn't feel anything while driving, though... maybe it happened relatively close to home? Noticed the flat on Sunday, swapped in the spare, and took it to America's Tire today morning. Apparently you can repair tires if the damage is in the tread area (as opposed to the side wall), and they did it for free! Fast, too - in and out in less than half an hour. Awesome.

Yosemite

Edit (2011/11/29): Added photos (finally)! Old entry (mostly trip logistics) at the end of the post.

2011 Yosemite

Orchid time-lapse

We got an orchid at Trader Joe's this weekend. This flower opened most of the way before we thought to start a time-lapse, but here's what we caught.

This video spans 20 hours. I'm using the xyster.net TimeLapse app on an iPhone 4, with the on-camera flash as the primary illumination.

Update (4/23/2011):

Saw another bud just starting to open and started a longer time-lapse. Same settings as before.

Elephant seals at Ano Nuevo

February 28:

Guided elephant seal walk at Año Nuevo State Preserve!

First of all, the California coastline in general is pretty awesome:

At the time that we went, the females had all left for the sea to eat, abandoning their pups on the shore. This process automatically upgrades them to "weaners". Our docent's talk of weaner this and weaner that was not met without the occasional stifled snicker. Also, I've always imagined weaning to be a more gentle, nurturing process.

We saw some of these weaners lying around looking like warts on the dunes:

They like to come together into groups, called "weaner pods".

Anyways, cute!

We saw a couple big males around, too. Elephant seals are known to be very aggressive and have intense fights for beach dominance. Their blubber is too thick for them to kill each other, but they do mess up each others' skin. After several fights, the skin in their neck area turns into a protective plate of scar tissue.

Today, they were all pretty inactive:

It was a particularly warm day, which contributes to their inactivity. They are very well insulated to withstand the cold open ocean, but this makes heat dissipation a problem while they're on land. Occasionally you'll see them flipping sand over themselves:

Tomatoes!

With spring definitely arrived, we stopped by OSH to get some garden plants: a beefsteak tomato plant and a small cluster of blue lake bush snap beans. They're both planted in a 3' window box (along with some garlic, basil, and other plants that also look like basil but are probably weeds)...we'll see if that's enough room.

New tank update

March 24:

New tank is struggling a bit. Blue-green algae has started to grow.

• Ammonium: 0 ppm
• Nitrate: 20 ppm
• Phosphate: 2.0 ppm
• pH: >= 7.6

Nitrate and phosphate are quite high, which is probably what spurred the blue-green algae growth. Perhaps it is leaching out of the soil? I can't imagine where else it could be coming from in that quantity.

Vacuumed the gravel and added some trumpet snails. Transplanted more stem plants from the old tank.

The old tank is holding steady in nitrate and phosphate, but ammonium is a tad high:

• Ammonium: 0.25 ppm
• Nitrate: 10 ppm
• Phosphate: 0.5 ppm
• pH: >= 7.6

Vacuumed the gravel here, too.

March 30:

Old tank is still 0.25 ppm ammonium. It seems otherwise fine.

Blue-green algae is coming in pretty thick in the new tank. Cleared out some manually and performed a 50% water change (nitrate 10 ppm and phosphate 1 ppm after the change). Started dosing Erythromycin.

Early April:

Water test after we finished dosing Erythromicin. Can't find the results now (wrote them down on a piece of paper), but I remember the new tank had high ammonium (0.5 ppm) and low pH (7.2) but everything else was typical values. Performed 50% water change.

April 14:

New tank:

• Ammonium: 0 ppm
• Nitrate: 10 ppm
• Phosphate: 1.0 ppm
• pH: 6.8

Didn't retest the old tank except to verify that its pH is still >= 7.6

Performed a small water change and will start trying to equalize the two tanks.

April 23:

New tank:

• Ammonium: 0.25 ppm
• Nitrate: 10 ppm
• Phoshate: 0.5 ppm
• pH: 7.6
• KH: 4°
• GH: 4°

Old tank:

• Ammonium: 0.0 ppm
• Nitrate: 0 ppm
• Phosphate: 0.25 ppm
• pH: 7.6
• KH: 5°
• GH: 5°

As you can see, we got a hardness test kit. I was concerned because the pH in the new tank was low earlier this month, but its hardness now indicates adequate buffering capacity. Strange that the old tank's nitrate is so low...I wonder if it's measurement error. I've always been suspicious of that second bottle of nitrate test reagent because you have to shake it before use.

Performed a 20% water change and am mixing water from the old tank into the new one. Possible signs of a blue-green algae revival in the new tank.

Fish tank setup update

Old tank:

• 10 ppm nitrate
• 0.25 ppm ammonium
• 0.5 ppm phosphate
• pH 7.6

New tank:

• 20 ppm nitrate
• 0.5 ppm ammonium
• 0.5 ppm phosphate
• pH 7.6

The ammonium in the old tank is a bit troubling; perhaps the nitrifying bacteria population isn't big enough without that giant floating plant mass acting as a nitrogen sink. Or maybe uprooting the transplanted crypts released underground ammonia? That seems unlikely. Anyways, the animals (nerite snail, shrimp, oto, 2 panda cories, 5 harlequin rasboras) seem to be doing fine.

Initially I thought the ammonium and nitrate in the new tank must have come from the soil, but ammonium levels have been around 0.5 ppm for a week now. I hope it's not steadily leaching from the soil (through 2" of sand); I think it's more likely to be decaying algae on the rock and the log (leftover algae from the old tank, dessicating for almost a year). The new grass seems to be doing all right; some of it has withered away but that just means the remaining leaves are thriving, right? Crypts look all right, except the leaves that I broke while transplanting it - those have died. Stem plants that I took from the old tank are all doing very well. The ones I'd taken from the floating plant mass don't look so good. They started out with smaller leaves, and now many of them have yellowed (probably dying) shoot apical meristems.

Today I did a 50% water change of the new tank and a 20% change of the old tank. 

MATLAB transpose

Big discovery for today: MATLAB's transpose function (denoted as ') is actually the conjugate transpose! The syntax for the non-conjugate transpose is .'

This caused lots of frustration today.

Fishes! An illustrated history, part 6

It's been almost a year since fish history part 5. Lots has happened in the meantime.

2010 Feb 13

We have a sad-looking java fern on the far left, some riccia tied to rocks, a few stem plants of different varieties (there's fuzzy plant, leafy plant, clover plant, and Stem Plant), some crypts in the foreground, a sword plant in the far back, an anubias over towards the right, and a banana plant behind it. There's also an anubias nana in the back right (it's not doing very well), as well as some four-leaf clover and pygmy chain sword scattered around (the clover is doing pretty well, but the chain sword is being shaded by the crypts).

2010 Mar 15

The riccia has grown intensely and is coming loose. Java fern is making a comeback, the crypts continue to thicken, and Stem Plant is growing quite long. The other stem plants are not doing as well. The last of the broad-leafed purple not-actually-an-aquatic-plant in the left is disintegrating. Nana has put out some new leaves.

2010 Apr 13

One riccia bunch has separated for good; the other is making good progress in that direction. Banana plant has sent up a pad to the surface, joining Stem Plant in forming a canopy over the aquarium.

2010 Apr 29
The littlest cowfish died :(

2010 May 16

Banana plant has sent a second pad up to the surface. Both are on some heavy-duty stems, maybe 2 mm in diameter. The sword plant in the back has put out new leaves, but its older leaves are growing fuzzy with algae and starting to die off.

2010 May 31

Did a lot of pruning. I trimmed the stem plants to the aquarium height and took out the riccia. The extra plants are all in the second tank now, acting as a nitrogen sink. With the mess of Stem Plant out of the way, we can see the other stem plants aren't doing as well. Fuzzy plant hasn't grown at all in the last few months, the clover stem plant is down to a single stalk now, and the leafy stem plant is losing old leaves without putting out new ones.

2010 June 1
A shrimp died :(  Also, we try to discipline the belligerent two-stripe rasbora, but that fails.

2010 June 10
Two more fish deaths: loner rasbora and old oto.

2010 Aug 28

The pads that banana plant sent up to the surface have come detached and I removed them. Java fern is quite full now, and the crypts are doing very well. I've been keeping Stem Plant trimmed. The other stem plants are slowly dying...I don't know what to do about that.

2010 Sep. 19
The big move! Pride Rock (the rock you can see jutting out in the picture above) has fallen over and the terrain has generally become flatter.

2010 Nov 13

Not much has changed. Terrain continues to get flatter; I think the army of trumpet snails is at blame. The clover stem plant and the leafy stem plant are gone, leaving only Stem Plant and two stalks of fuzzy plant.

2011 Feb 21
Banana plant has floated away and the fuzzy plants were overcome with algae. But today we took the next step towards the fish tube, a contraption I first alluded to almost a year ago!

I used xyster.com's TimeLapse app (v4.1 for iPhone 4) to make these videos.

That first segment was 2 hours. This next one runs until the iPhone battery dies:

No captions above; I'm just adding more clean water and straightening the plants.

And that leaves us with this:

Ammonium is high (1 ppm), so I'm going to let it go for a few days before reintroducing the trumpet snails (they're hanging out in a bucket right now) and setting up the fish tube. It'll be interesting to see the progression of this tank!

2011 Feb 22
Ammonium down to 0.5 ppm now. I think that initial spike came from the soil; hopefully the 2" of sand will keep that from diffusing out too fast. The plants are also supposed to absorb ammonium preferentially over other forms of nitrogen.