Aquaponics

I’ve done aquaponics – which is basically using fish to fertilize the water you use to grow plants hydroponically – out of the Battlestar before but this is the first time I’ve done a fruiting plant. I had a volunteer cherry tomato show up in my back garden thanks to throwing moldy tomatoes out for the squirrels. It got nice tomatoes on it before the end of the season so I decided to take a couple of cuttings and try growing it inside. Basically all I did was stuff the cuttings into some plastic pots with clay hydroponics substrate that I wired up to sit on the top of the tank and then let nature take over. Only one cutting ended up rooting and taking off, but boy has it grown.

tomato plant sprawling on the top of a large aquarium

Here it is 20 days ago, finally  getting its first fruits. The roots are on the other side of the glass tank cover. The light source is a AquaUFO + Red LED fixture.

On the other side of the tank I have my giant mass of watercress and some Garnet Rose Lettuce starting.

Lettuce seedlings sprouting

Here’s a picture of the whole tank. We’ve got the top wrapped with black paper because the LEDs are so bright that they make tv watching impossible. They’re also pretty uncomfortable to look at directly, although not dangerously so. Please excuse the state of the tank as I really needed to clean the filter before I took this picture. The aquatic plants at the bottom aren’t edible and have been in there for years. It’s mostly a mix of cryptocorynes and tiger lotus (Nymphaea lotus) as that seems to adapt best to the constantly changing light conditions and my lack of attention.

large aquarium with plants growing out the top

Twenty days later, we’re really cooking now.

The whole tank

It’s a bit hard to compare because the lighting conditions make photography tricky, but the tomato plant now spreads from one end of the tank to the other and has branches up to almost the ceiling. I did clean the filter so there’s less murk. I also had to change the position of the powerhead I have in the tank so it’s blowing the root ball of the tomato to the front of the tank. Makes for a somewhat less attractive showcase tank, but it’s fun to watch the fish hunt for food and spawn in the roots. My diamond tetras reproduce in the tank pretty regularly. I have less fry lately because of the addition of some more predatory fish, but eventually they’re going to be too big to comfortably be able to fit in all of the root structures and I’ll see more fry again.

Tomato Plant

Behind the light guard, you can really see how the tomato plant is covering the top of the tank. I’ve got tons of flower, young fruit and two ripe tomatoes! Jason tasted one of the tomatoes last night (because I don’t actually like them!) and said it was a completely perfectly ripe tomato with excellent flavor and sweetness. I am very excited to have them continue to succeed!

On the other end of the tank, the Garnet Rose Lettuce is starting to leaf out and turn a beautiful red. This is a new breed for me and I’m looking forward to tasting it.

Garnet Rose Lettuce seedlings

If anyone has questions about fish stocking, feeding, or any other specs, let me know.

Aquarium Projects: Crab Paludarium

Whole Crab Set-up
This is my latest aquarium project. It’s actually a paludarium, which basically just means that it’s a terrarium with both land and water area. Because the red devil crabs (Geosesarma spp.) I wanted to keep are primarily terrestrial, I needed to have a lot more land and hidey holes than I needed water. But they do need humidity and moisture and I didn’t want to invest in an expensive fogger like some people do for reptiles and frogs. So I wanted to have a small water area that I could pipe to a spray bar and keep the entirely thing damp.

To start, I picked up an Exo Terra terrarium. I like how it opened both in the front and back. The foot print was small enough that I would be able to find a good place in the house. I also liked the foam background it came with since I figured that would be easy enough to pipe the waterworks through. After this had been up and running for a while, I discovered two things I didn’t like about it. First, it leaks. There’s no good indication of how high to fill the water without trial and error. It’s a slow drip, but it’s a good thing that I’ve got a drip plate underneath it on the stand because it can be a substantial amount of water if I’m not careful. Second, because I wanted to keep the humidity in and not have to worry about topping it up every day, I placed pieces of Plexiglass on top of the screen top. It turns out that even though it’s intended to be used for damp environments, the screen wasn’t rust proof! It started rusting and then disintegrating very quickly. I ended up having to pull all of the screen out of the top and rescreen it with some vinyl coated screen I had bought for our screen doors. Not only was the screen held in with cheap spline, but then the screen and spline was glued into place. It took me ages to get it all removed. I feel very lucky I didn’t end up breaking the top’s plastic frame. However, once I had the screen replaced, the Plexiglass works well to maintain the humidity.

For the waterworks, I’ve got a cheap little aquarium pump to move the water from the bottom to the spray bar. I had a really hard time finding something that wasn’t giant and would work well in the low water level. I found this little one at Petco and only spent $20 on it. However, because I only spent $20 on it, I also don’t expect it to last very long. As another minor grumble about the terrarium, the holes cut into top to pass wires through were cut so that the opening of the hole was smaller than the hole itself. So while the cord for the pump would fit in the hole, it wouldn’t actually get through the opening. And when I tried to press it, the plastic was sharp enough that it started cutting the plastic coating on the cord! That’s not good. I ended up using a razor to cut the opening larger and that solved the problem. One of my design priorities was making sure that I could easily replace things as needed. So I didn’t do anything like glue the background into place like I’ve seen other builds of this type do. The hoses and spray bar are spare Eheim canister filter parts. I did end up having to cut the spray bar down in order to fit it in where I wanted it, but that was fine. I also used plastic zip ties to hold hoses in place against the foam background. Cheap, easy to use and replace, and I don’t have to worry about them corroding.

One very specific piece of hardware I wanted to mention was the heater. I got a Cobalt Aquatics 25 Watt Neo-Therm Heater with Plastic LED for this tank. You can find a lot of betta heaters out there for small volumes of water (and all told this tank holds maybe 2 gallons tops) but most of them just raise the temperature 5°F with the assumption that the tank is going to be somewhere with a steady room temperature of about 75°F. That is not the case in my house so that would lead to a lot of temperature fluctuation and possible overheating. This heater, however, comes with a built-in thermostat. It tells you what your set temp is and what the water temp is, if it’s below or above the set temp. It’s very neat and thus far I’ve been really happy with it. In fact, I really ought to pick one up for my office shrimp tank since my office is quite variable in temp and I just have a static betta heater in there right now. I also like that the heater is fully black except for the LEDs so it’s hard to see in the tank.

Finally, the lamp on the tank is a cheap hanging spotlight that I’ve had for over a decade on an Exo Terra lamp holder. I like how simple the lamp holder was and adjustable. I initially started out with an incandescent bulb in it, but quickly discovered just how much heat the bulb put off when it quickly burned and killed the plants I had highest up in the tank. Oops. Now I’ve got a full-spectrum LED equivalent of a 40W bulb in there. It doesn’t put of nearly as much heat and seems to keep the plants happy.

So that’s the hardware. Now for the hardscape. I used plastic hydroponics cups and PVC pipe as the bones of the hardscape. Again, I wanted something that I could move in and out easily in case of needing to do mechanical repair. Everything is held together again with plastic zip ties. It’s more mobile than something glued together would be and probably a bit more unstable than some people would like in their tank. I wanted the flexibility more than anything. Then I covered everything with bark glued on with silicone. Since these are rainforest crabs, I wanted them to have “trees” to hide in. Also having the texture gives them more things they can climb. At the time I was setting this up, my local fish store didn’t have any cork bark in stock for ages. I ended up heading out to the back woods and picking up bark pieces out of the driftwood piles left by our local creek’s floods. This lead to some really interesting mushrooms and fungi growing when I got water and heat running in the tank. There’s also some tiny insects that may have come with the bark that are too small for the crabs to be interested in eating, it seems. They do act as a decent clean up crew right now since there’s not snails or similar scavengers in the paludarium. Since then I’ve picked up some cork in case I need to replace things in the future. The wild bark is holding up okay, but I suspect it may break down faster than cork would over the long term. Also, it turns out, silicone doesn’t hold things together particularly well once it gets wet. I’ve had a couple of pieces of bark come off the cups since I started running the tank a few months ago. They’re thankfully in the back of things and are quickly being covered in moss. The cups’ mesh would have let too much of the peat/soil/sand substrate out so they’re lined with the same vinyl screen screen I used on the lid. I wanted to keep the drainage without having too much substrate leak out. This seems to have worked pretty well. The places where it came up past the top of the cup have also become great places for moss to grow.

Finally, the substrate on the floor is just plain black sand. I figured that there would be a decent amount of organic material washing out of the cups as things settled so I didn’t put dirt in the bottom of the tank like I do with almost all of my other planted aquariums. This might end up working against my plans of having aquatic plants on the bottom in the long run, but you can’t really see much down there anyway with the cups taking up so much of the tank.

It’s currently planted with java moss, cryptocorynes (C. wendtii, I think), and some Cape sundews (Drosera capensi). I did have a Nepenthes pitcher plant in there, but it was unfortunately one of the plants that ended up cooked by the incandescent bulb. I also tried to get some baby tears (Hemianthus micranthemoides) going, but I don’t know if it just didn’t like conditions or what, but it’s mostly all disappeared since the picture at the top was taken. The crabs do dig, move things around a bit, and possibly eat plants, so the only sundew that seems to be hanging on is one that hangs off the top of a cup. The java moss is covering everything quite nicely. I planted the crypts in the water with a bunch of their leaves emersed. I hoped that since a lot of the aquarium plants you buy are farmed emersed that the crypts would keep their leaves but thus far they’ve died off to below the water line. Perhaps as they grow they’ll start putting out leaves above the water line. I have some bladderworts on order to try out in this tank. I wanted some more carnivorous plants and decided bladderworts would be something different to try. I have Utricularia longifolia and Utricularia sandersonii coming this week. The first is supposed to have nice large leaves which would be a nice look. The second is supposed to be quite an aggressive grower (possibly even invasive) but I’d like to get some good growth going and the possibility of a lot of flowers in the tank sounds really nice.

This set-up has been running for over four months and has had crabs in it for over three. There were initially 8 crabs in there which was probably a few too many, but since they’re kept at the fish store in a purely aquatic tank, I was concerned (rightly) that not all of them would adapt back to the mostly terrestrial environment well. I know I’ve lost at least three of them so far and have only been able to spot four of them at one time recently. You wouldn’t think bright red and purple crabs would be so hard to spot in the tank, but once they retreat to the shadows, they’re almost impossible to spot. I was hoping to keep six so that I’d have the best statistical chance of having a male/female pair but four is good too. They’re generally pretty shy about movement in front of the tank. They’ll either go into hiding or freeze for a long time if you move suddenly in front of the tank. However, if you approach carefully and keep still, you can often observe them climbing around the cups, looking for food. I’m feeding them pellets formulated for crabs and shrimp and those seem to work pretty well. They will also hunt live crickets very successfully. These little guys can really move when they want to. It can be a bit disconcerting sometimes because their movement is a lot like that of jumping spiders. They’re really neat little critters. I’m hoping that they may start breeding eventually, but if they don’t, they’re still neat to watch.

Close up crab

Crab standing on some bark and moss

Ricefish and fry

This is my first aquarium. Well, the bones of it were my first aquarium. I originally got into the hobby because while visiting a now defunct local store, I discovered the Moon, or Halloween, or Patriot, Crab. How can you not love a purple and orange crab the size of your hand? I mean, really. So like a good novice, I went home to do some research. It turned out that I really couldn’t set up a good habitat for them, but I could set up something small for red clawed crabs.

The tank originally looked like this:

Brackish tank from front 3-28-07

I created a couple of cliffs from siliconed rocks that I filled with sand and plants. I had an ironic castle. It was amazing. You can see my noobery from the fact that I didn’t un-pot the java fern.

I had a couple of crabs and a couple of mollies and platies that I acclimated to brackish conditions. They did all right for a while, but eventually the deep bed of sand I had created on the left side to give the crab air access got all gross. The crabs all managed to escape and I finally just said screw it and turned it into a planted tank. I torn the cliff face in half and created a couple of terraces out of the pieces. You can see it right after in the picture below.

Redone tank, view from front

There have been a lot of different residents over the years. The longest resident was probably Right Bastard, the bastard paradise fish. This fish could hold his own against African cichlids. He had the tank to himself for a quite a while.

Look at this handsome bastard.

RB disapproves of this photo

RB is long gone now, sadly. We now have this tank in the bedroom and the current residents are a trio of ricefish (Oryzias sp. No idea which species. The cheaper ones.). For a while there had also been some loaches in the tank, but they died off while we were on vacation. With these egg predators gone, I’ve had fry starting to show up. Right now they range in size about a centimeter long and a half a centimeter tall for the oldest to about 6 millimeters long by maybe a millimeter thick. The newest ones are even harder to spot because their eyes don’t have the distinctive blue shine yet. I spend a lot of time staring at the underside of the water’s surface to try and get a count of fry. I think there’s about a dozen or so at last count?

Below is a video of the fry and parents I took on July 20th. You’ll have to forgive the cyanobacteria (blue-green algae) in the tank. I had a dead flow spot caused by the bladderwort that let it get a foothold. I’m hoping that doing water changes every other day will help kill it off. I hate that stuff. If it doesn’t, at least the water changes will be good for the fry. It’ll be nice to have a full tank of fish again.

There’s also a female least killifish in the tank, a refugee from a tank I intended to tear down until my husband stuck a bunch of angelfish fry in it. There’s also a last red claw shrimp from a breeding population that was in the tank for a while. I’m thinking to replace him with some Neocardinia shrimp once he dies although I’m not sure if I want to try to be fancy or just get some cheap cherry shrimp off Aquabid. I’m mostly just looking for a grounds crew and don’t really want to get any other fish as I’d rather have the ricefish keep breeding successfully.

All-Aquarium Catfish Convention

Coming up next weekend is the All-Aquarium Catfish Convention sponsored by one of my local aquarium clubs, the Potomac Valley Aquarium Society. I, unfortunately, cannot attend the whole conference, but I am planning to be there for the auction on Sunday. Not going to buy a lot (hopefully!) but I’ve a couple of cichlids to rehome and I’m in need of some plants now that I’m finally starting to get some growth in my amazon tank. I do Walstad-type soil planted tanks and they usually do really well for me, except after I had to redo one of my 125s after it got broken by tile installers. My adult Geophagus steindachneri kept disturbing the soil so much that the water was too murky for the plants to get much light. Between that and the initial tank break, I lost a lot of plants and what survived just weren’t growing. Since I’ve removed the cichlids from that tank, the plants finally started to recover and I really want to put some more in there. I have a school of keyhole cichlids that would really like some more cover so I’m hoping to get some large-leafed sword plants. I also just this weekend added a really fantastic, large piece of wood that needs a number of java ferns tied to it. These auctions usually have a lot of java fern for sale so I’ll actually be thrilled for once when the 100th lot of the stuff comes up. :D

In keeping with the convention theme, my husband is looking for some catfish for his uaru tank. Some bug got in there and took out a bunch of his corydoras so he needs to replace them. I’m trying to talk him into some porthole cats, but it will depend on what people bring.

Are you going to the All-Aquarium Catfish Convention? What are you looking for? What are you bringing?