Leni

I have 3 mollies in my community tank (had 4), 2 females and one male (had 3 females). I haven't seen any aggressive behavior myself, but I found recently one of my zebra danios dead, and yesterday, one of my female silver molies was dead too. There aren't any water quality issues in my tank (7.6 pH, no ammonia, nitrates or phosphates, and I'm dosing my tank with aquarium salt and water conditioner every time I do a change, and my liquid plant fertilizer every week). I think the male molly is bullying the other fish at night (I've always found them in the morning). I don't want to have to buy another tank to put the mollies in, but I'm getting sick of finding my other fish dead. Is a tank just for my livebearers the best course of action? I can always move my danios into my 55g once it's set up and ready to go.

Tony G.

Hello Leni
What i would do is stay up a little later than usual and keeep the lights off and everything. Watch them closely to see who the culprit is. Also, you stated you have no issues in the tank. I think you must have been confused because nitrates are good and nitrites are bad..

keep a close eye on them

Shawnie

im sorry for the loss of your fish
do you have a salt testing kit? allot of our fish we get arent use to salt and salt doesnt dissipate unless you remove it with water changes..you could have too high of a salt concentration....you definately had the right ratio of m/f so that shouldnt have been an issue...ph is a bit high but im sure they have acclimated by now to the higher end....try doing a few water changes without salt and just your water conditioner ...is the tank heavily planted? and what are the readings for your nitrites? if it was an issue of a bully, you would see it and it wouldnt happen just at night....

Leni

All my test kit readings are zero (minus salinity and anything hardness-related, I don't have those). Most of the ammonia in my tank is taken out by the plants before it has a chance to turn into nitrite. The salt should be dosed correctly - I initially put in the recommended rounded tsp/tbsp during my cycle (I can't remember what is on the box) and every change I just pour a few crystals in (I usually change about 2.5g once every 10 days, with a topoff once a week for evaporation), so it's always had salt in it. I suppose I could get a salinity test kit, but I'm pretty sure it's not too high. I'll have to sit up and keep an eye on the molly one night, I guess. I'd say the tank is moderately planted, but it's all vine-type plants except for a single sword plant, so there's not really any place for a distressed fish to hide except in my plastic cave (which is where the kuhli loach and the algae eater like to chill).