I'd been looking for a way to raise up smaller fry such as cories, rainbows, and rams. During the first few days after hatching there were always big losses. My solution is these fry boxes. Several of our club members thought that the fry were probably starving to death. Even though I'd been feeding them large amounts of live foods, some of the fry were never able to find their dinner. As soon as their yoke sac was absorbed, they'd expire. After an amount of trial and error my solution was to concentrate the fry in the small container and make small but continuous water changes to its small volume. This way they'd be literally sitting in their food and still swimming in clean water. They couldn't help but eat. The system of continuous water changes insured the little fry tank would not foul.
Included is a drawing of the setup. It involves a sponge filter with a lift tube and suction cups, a rectangular specimen container with a hole cut in it, a few PVC fittings, and a screen. A few points to note while looking at the drawing:
The sponge filter is attached inside the main tank wall at an angle. The output of the filter lift tube continuously drops clean, filtered, and aerated water into the specimen container with the fry. I use a sponge taken from an established tank.
The specimen container is hanging inside of another large tank. Fry are kept in this container for around a week. The main tank may or may not have other fish in it. Often it's empty of other fish so it can become the next home for these fry after they've outgrown the specimen container.
A ¾” to ½” PVC bushing and a ½” slip PVC street ell bought from the plumbing isle of the hardware store were used for the fittings. A Dremel tool was used to cut a hole near the top lip of the specimen container for the bushing. The bushing is glued in place with aquarium silicone. The ell is a slip fit in the bushing so that it can be removed to clean the screen or rotated to adjust the water level in the specimen container. The first version had the screen right on the bushing, but then I had a hard time doing the daily screen clean. When the ell and the screen are just slipped onto the bushing they can be removed, rinsed, and replaced without disturbing the fry too much.
The screen took the most trial and error. The first try was a chunk of sponge inserted into the ell. If too much sponge was stuffed in the hole, the water wouldn't flow through. Then the water overflows the top, the fry swim out, and are lost. Too little sponge and the fry would get trapped in the loose sponge fibers and die. Several types of sponges were tried. Cheesecloth always clogged too easily. Finally I settled on a little piece of women's panty hose. I cut out a piece about an inch square and then stretched it over the end of the ell. A rubber band holds it in place. If it's stretched real tight, the screen holes are real small, if it's left loose, they are comparatively large. It's sort of a built in adjustability that you can change in relation to the size of your fry.
Microworms work great in this setup. They settle to the bottom and stay away from the screen. The screen will stay clean for days with these. Baby brine shrimp clog the screen after a day or two, which isn't too bad. Dry foods clog the screen quickly, so I avoid those.
Try to adjust the air flow in the lift tube so there is drip every second or two. Much more and the container will overflow and you'll loose the fry. I set mine so that it maybe completely exchanges the water in the container once an hour.
I've set this up in nearly all of my tanks at one time or another. Try and avoid putting it in a tank with larger fish. If the screen gets plugged, the fry will swim over the side and get eaten.
So far the system works better for me than a dedicated small tank. The fry and their food are more concentrated. The temperature and water conditions in the large tank are more stable.
Several of these containers are ready to go most of the time. If I notice that the inside is getting scummy, I just tip the old container, water, fry, and all, into the clean one and start over. If I try and clean these containers when they contain fry, often the fry get accidently squished. Have an extra ready to do the dump and switch and you won't have that problem.
When I was thinking this over last year, I bounced my ideas off of several members in the club. Dani Elickson, Rich Smarchz, and Lenny Ancheta are all using something like it or have tried their own version. All have successful fish rooms. Give it a try and you too may be able to raise up some of the smaller fry without too much trouble. Let me know how it goes, I'd love to hear any feedback or success stories you might have to offer. |
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