Switch from goldfish to tropical

[maryholland]

My tank is a 70 gal with a fluval 404 canister filter, two hagen power heads run on reverse flow with an undergravel filter. The gravel is medium size"creek bed". The lighting is a double fluorescent strip. I also have an in line uv filter. This set up is 5 yrs old. Currently I have one koi, one panda oranda, one ryukin and two telescope butterfly orandas. The koi is a youngster who will be ready for the outdoor pond in the spring. The remaining fish I plan on giving away. I want to switch to tropical freshwater fish. Other than a heater I really dont know if or how I should modify the set up. I am also uncertain as to which fish to start with. I absolutely love dalmatian mollies. Currently I have plants which I replace about every ten days because of the koi. The koi just shreds them in days! With this set up and fish load I have no ammonia and nitrites. The nitrate stays steady at 30ppm. The ph holds at 7.8. The water is moderately hard. I dont really test for it as the goldfish and koi are not too fussy about it. Where do I start in converting to tropical freshwater?

 

[ringfinger]

The 404 will work great, but I don't really think the undergravel filter is necessary or really something you would want. A good heater like a Visi-Therm, maybe two with one at each end of the tank. Now you just need to decide if you are planning on live plants. Now would be the easiest time to switch substrates.

 

[Fishyfanatic]

I agree, ditch the ugf when you move the fish. All you really need is the heaters. I would go with two 200 watt heaters, something like the Visi-Therm Stealth.

Welcome to AA!

 

[maryholland]

Grateful for the advice and information. Will use it!

Thank you for the advice. I am looking forward to ditching the ugf. I have make a kind of snake siphon that wiggles under the ugf through the uplift tube openings to keep it clean under there but it is a pain. The stuff you clean out of there is really good houseplant fertilizer! I am planning on plants in the tank, so I will probably switch the substrate. I dont think I am ready to put in a co2 system at the start but I am considering it. My primary interest is in the fish. Any suggestions on good companions for dalmation mollies. Since I will be switching the substrate this will be a "new tank" which will need to cycle so I won't jump into a lot of new fish all at once.

 

[Fishyfanatic]

Pretty much any peaceful fish will do well with Mollies. Perhaps a few schools of Tetras, bottom feeders, a pleco, some snails, a few center piece fish, and the mollies? Make sure the mollies are of the same sex otherwise you will have SO many fry.

 

[maryholland]

Thanks for the warning regarding the mollies. I had a lot of goldfish fry last year from the orandas. Center piece fish? I think I need to do some studying up!

 

[rich311k]

Angelfish, gouramis, and rainbow fish would all make nice centerpieces.

 

[Fishyfanatic]

Centerpiece fish are basically fish that stand out in the tank. They catch your eye when you glance at it. They are generally larger than the other fish. As Rich pointed out, Angels, Gouramis, and Rainbows are great options. I consider my Rams to be my centerpiece fish beacuse of their striking coloration. And once they get to their adult size, they will defiantely be the largest in the tank.

 

[kaz]

lets not leave the beautiful chichlids

 

[maryholland]

You guys are sure making me impatient to make the switch! As soon as the water temperature is ok to move the koi this spring I am tearing the tank down and starting over. Any suggestions for the substrate/gravel? I plan on getting the visitherms. I like the idea of two. It seems that if one fails you can get along with other one until you get a replacement. I am also guessing that the tank might be more evenly heated. Correct me if I am wrong, please. I am going to get some tropical fish books to try select a community tank that will all do well with the water here. I currently use an inline filter (System IV) to fill the tank. It filters out chlorine and other stuff. The tap water here in the winter tests at 10ppm nitrate due to fertilizer runoff.

 

[Fishyfanatic]

Any suggestions for the substrate/gravel?

I like sand because I think it looks more natural. Pool Filter sand can be purchased pretty cheap (50lbs for $6) at any local pool supply store.

I plan on getting the visitherms.

I recommend the Visi-Therm Stealths, VERY good heater.

I am also guessing that the tank might be more evenly heated.

You are absolutely correct. Plus, if one heater malfuntions, you have another heater for backup until a new one can be purchased.

 

[frenchpea2002]

when you tear down your tank, keep your filter media, since that will seed the cycle and pretty much eliminate any ammonia spikes, especially if you start with a small bio-load, since you will loose quite a bit of bacteria while switching out the substrate, but at least you won't have to start all over. Many fish will go great in a 70, but my concern is with Mollies is they require quite a bit of salt in their water (some even consider them to be brackish fish), which other FW fish may not tolerate...

 

[Fishyfanatic]

I wouldn't even mess with salt. It isn't really needed with mollies anymore since they have been bred in captivity in freshwater tanks for so long. If you obtained several wild-caught mollies, then definately. But otherwise, I wouldn't worry about it.