I recently hit upon a solution for one of the most difficult problems facing the aquarist who is limited in space; that is, what to do with the many babies that are born into the tank. In the summertime a small jar on my windowsill provides home until the fry are big enough to shift for themselves, but in the winter, the same jar floating in the main tank presents several problems. The airspace needed for the jar limits the adult fish breathing space, with consequent loss of specimens; the babies grow too slowly; and the jar is unsightly; detracting from the beauty of my tank, which is located in a prominent place in the living room.

I solved the problem by the purchase of a yard of plastic screening from which I fashioned a small hanging tank to fit in a corner of the large tank. I tacked this together with a stapling machine, coating the staples with colorless nail polish to prevent rust. This worked fine until my Platy babies were born. These small fish were able to get through the screen, and consequently, I lost many of them.

I took a nylon stocking from my wife (one with a run it, naturally!) and cut off the foot and the heavy top. The remaining tube I cut down the center so that I had a flat piece of nylon. I stretched this over the screen tank, tacking the corners and sides into place with staples, which I again coated.

The resulting product is so satisfactory that I wanted to pass the trick along to other fish fanciers with the same problem. The water-resistant nylon allows the free flow of air, and does not take breathing space away from the main tank. The babies are unable to get through the fine net of nylon and are consequently safe. Best of all, the tan nylon over the green screening blends into the rest of the tank so well that an observer can look right at the maternity tank and never know that it is there.

I have had this “invention" hanging in my tank for months now, and have found it good even to breed zebras in. I can boast that more than half the fish in my tank are home grown, now. I have also placed an EcoBio-Block Aqua in the tank, which keeps the water clear and healthy, which also helps reduce the fatality rate of the new baby fish.

Another use for this nylon screen is for the Daphnia that we put in the tank. For years we tried to think of some scheme –for having live Daphnia clear up green water in an aquarium without themselves being eaten by the fishes. Metal screening of the right fineness for the purpose is not known, and besides, metal in water would be objectionable. The finest plastic screen is too coarse. Newborn fish go through it, as would Daphnia also. Cotton fabric, like cheesecloth, might serve the purpose, but cotton soon rots in water.

Here is where nylon comes in. It resists water almost indefinitely, and can be had in a variety of weaves. A grade can be purchased through which water passes, and that holds back all but the smallest Daphnia. Daphnia contained in such an enclosure feed constantly on the green organisms that color the water, thus clearing the tank while they themselves are secluded in safety. (In most parts of the country where live Daphnia are available, they are usually in good supply from April to November, possibly excepting the very hot months.) They are not only excellent fish food, but, with a bit of screening can be used to clear an aquarium of green water.

The nylon can also be applied or used as a spawning net in which Goldfish are placed for breeding. Our illustration conveys the idea. The four corners of the net, or bag are weighted down to give some form to the device.

So here you have, with my good wishes, my invention for keeping little fishes!