Hi,

I'm growing out a bunch of goldfish fry. I have a 40 gallon tank with tons of filtration on it, (2 aquaclears and a mini-reef filter). I agreed to grow the fry in 300 gallon tub outside but it is still too cold to put them out. I have a malaysian pearlscale, 3 inches and very fat, and a crown pearlscale, approx. 4 inches. in the tank along with 30, 1 inch fry. Ammonia began to creep up so I transferred the fry to a 60 gallon tub (inside). Four days later, I tested the tub water and was horrified to find the ammonia at 1!!! I immediately transferred all the fry back to the 40 gallon tank and noticed that some of the fry had inflammed gills. (poor guys) I know the 40 gallon is going to be too small for all of these guys until the weather gets warm enough to put them outside (probably at least a month, I'm in Canada). I don't want to endanger my two guys. Why did the ammonia spike so quickly in the tub? Is there a cheap filter I can construct to establish some sort of cycle in the tub to handle the ammonia? Also, if I have to keep them in the 40 gallon tank, would feeding the fry sparingly (to control the ammonia) adversly affect their growth long term? One more question, (sorry for the long-windedness), can I make a filter for the 300 gallon tub for a low cost? I'm growing these as a favour and don't want to spend a fortune as I won't be keeping the fish.

Thanks in advance for any advice.

Angela

Angela, I had pretty good luck with cheap rubbermaid containers as homemade filters. I prefer the 20 gl size (give or take a few gl), and if I need a quick filter, I only need a few little things.
A powerhead from Walm*rt (they lay around in my house by the dozen), the rubbermaid, some cheap tubing to connect the powerhead to the rubbermaid, and a sharp knife to cut some holes into the rubbermaid on the side.
I just have the hose go from the powerhead into the rubbermaid, where I stuff all the filter media from cycled filters in there, so there is already beneficial bacteria in the filter. Stuff it with some extra media - cheap floss from the craft store will do, the kind you stuff pillows with. Comes for a dollar or two in a bigger bag. The holes are cut into one side of the rubbermaid, whereever you prefer, and thats the output of the filter. Stick the rubbermaid on the edge of the tub, maybe on a stack of books, and position it so that the water runs back into the tub. Voila - instant filtration. You can stick a few plants into that rubbermaid as well, I prefer something called a spider plant, at least around here, and it doesn't need soil or anything. Pothos works well too.
I think I have a picture of one somewhere, let me look....

Thanks! If you could find a picture of your setup that would be great. Unfortunately, I think the original ammonia rise in my 40 gallon may have affected my pearlscales. One has a red mark on it's side, and the crown pearlscale looks like his fins have a white fine powdery coating and are frayed. I was going to add Pimafix as it claims to help both of these conditions. However, I am afraid to mess around with the water for fear of another ammonia spike. (keep in mind, the 30 fry are back in the 40 gallon) Does Pimafix affect the cycle? Also, the white powdery coating does not look like ick. What else could it be?

Angela