Hello all. I have a silver lyretail mollie in a 20 gal. long tank with one wagtail platy, another black mollie, four guppies, an approximately two inch honey gourami and two oto cats. My concern is that my silver mollie is just sort of shimmying, moving rapidly back and forth horizontally and darting around, but not really flashing or rubbing up against things. I changed substrate from play sand back to gravel a week ago but was careful to thoroghly clean the tank, keep about 50 percent of the old tank water and make sure the beneficial bacteria in the filter didnt died off since my tank is cycled. I just now checked water params and ammo, nitrites and nitrates are all at zero. I know in theory i should have some nitrates but the tank is at least three months old and I just never have had nitrates after the cycle was finished. i am more concerned about my fish. help please. Thanks.
As long as you did not overly clean or replace your filter media, your water quality should most likely remain safe. Almost all of the bacteria that you will typically need will be in your filter media and not the water
Lyretail mollys can get as big as 5 inches and can also be a very active fish making them not the best suited fish for a 20 gallon tank. This might be a part of the reason for the odd behavior if your water parameters are fine
If you take your time to do the research FIRST, you can successfully set-up and keep ANY type of aquarium with ease.
"Not using a quarantine tank is like playing Russian roulette. Nobody wins the game, some people just get to play longer than others." - Anthony Calfo
Fishless Cycle Cycling with Fish Marine Aquarium Info
As for having 'zero' nitrates, whether that is an issue depends; if you do large water changes weekly or moderate ones bi-weekly, than 'zero' nitrates are possible in a twenty that has a good level of stocking. Otherwise, might be the kit (too old or not mixing well.) You did not post your water changes (number per week and size) so we are lacking a critical bit of information.
One thing I will say, mollies can be treated with salt and respond well to it; however, other fish you have, not a good idea. If the mollie continues to have issues, consider a separate small tank and use salt. Use 1 tsp/gal of water and MUST be Kosher or std fresh water aquarium salt.
Just remember that daily, near 100% water charges (with salt replacement) are required in any new tank since it takes a long time to cycle a new filter (and the fish should recover well before then, anyway.)
Speaking of which, a near 100% water change (IF and only if the tank and your tap water pH match within 0.25!!!) could help the fish. If the pH's do not match, depending on the difference, try changing the largest volume that does not change tank pH by more than 0.25; then repeat this a few days later and keep it up until the fish gets better (hopefully.)
Last edited by Cermet; 09-22-2013 at 01:27 PM.
Knowledge is fun(damental)
A 75 gal with eight Discus, fake plants, and a lot of wood also with sand substrate. Clean up crew is down to just two Sterba's Corys. Filters: continuous new water flow; canister w/UV, in-tank algae scrubber!! Finally, junked the nitrate removal unit from hell.
For Fishless cycling:http://www.aquaticcommunity.com/aqua...ead.php?t=5640