View Full Version : Help! My fish are dying

Disco Dean
04-30-2008, 12:51 PM
I need some help.

I am a newby but have some solid help from experienced friends. I have had my tank now operating fine for more than a year. But, I have lost 4 fish in 2 months. The tank is a 35 gallon - with two filters rated for a total of 70 gals (overkill but I have them so use them) I have some plants - Anubias, Redtemple, Fanwort... all that have been healthy in the tank for months.

I lost a Danio - then a Platy - then another Danio - then my Danio's starting to show signs of mating - my two females got very large and sat near the bottom with males close by... one of them got very big - so big that it looked uncomfortable and her scales started lifting a bit around the back of her head. Still active and feeding. Now she is dead today. I do not have a breeding tank so have left them to their devices.

- no food change
- tank is 77 degrees
- water tests perfectly (if a little bit hard) but the same for the year
- total fish before dying - (2 gourami, 3 platy, 1 oto, 5 danio) - a lot of fish but they have been healthy like that for a year... ???
- two snails for the algae

I have had a slight algae bloom - when the light changed this spring in the room - green, on glass but the fish started dying before that.

I am trying and I know making some mistakes but I am worried about the fish suffering and dying.



04-30-2008, 01:22 PM
Have you introduced any new fish or tank decorations recently? Is your tank near a window? You mentioned algae bloom recently.

Disco Dean
04-30-2008, 01:43 PM
No new decorations that haven't been in the tank for the duration and set-up. The tank is to the side of the window - but gets a bit more sunlight now that the spring is here. The algae is not that bad but it is new - water still tests exactly the same though with my kit.

I know we had too many fish in the tank to begin with and lost a two at the beginning to I think a little stress and also the tank and fish settling in - that was in the first two months - since then - almost a year - no problems at all. Water changes once a week (5 gallons). We had ich for a spell about 5 months ago and cured that. No signs of any marking or other diseases. I can't see any reason why. Unless the Danios are not pregnant and they have an internal parasite...

Lady Hobbs
04-30-2008, 01:58 PM
You need to shield that side of the tank from the direct light. I run my background paper around the side of the tank to cover my side up that is near the window.

Your water tests might be find but are you doing regular water changes. And feed those platies sparingly. They will eat themselves until they are huge and constipated. Letting them go for a day now and then is beneficial to them and feeding only once a day for that species is ok.

Other than that, I can see no reason you could be having a problem. Do you know what your pH is?

04-30-2008, 02:19 PM
Hi , How Often Do U Clean And Change Water

04-30-2008, 02:20 PM
oh and how much water do u change , dechlorinateror leave to stand ??

Disco Dean
04-30-2008, 02:30 PM

I will shield that side of the tank - the algae is not that bad but I might no know what bad is.

When I change the water out it is a 5 gal water change once a week. The two filters are set-up one with charcoal the other with ammonia remover so they work well in tandem I think and help with the populated tank.

The Platies have been pretty solid actually but I think the Danio's are killers on the food - frenzy for it.

I feed small amounts once a day - with a shrimp cube once a week or two weeks.

The Oto seems to be eating some of the algae and the snails have started doing a good job at it.

I have NOT checked the PH - and it tests a bit hard but it has been consistent for the year at that level. Our tap water is very very good and completely free of chlorine so we are lucky. Nitrate and Nitrite are clear.

04-30-2008, 02:36 PM
well all i can suggest is the dead fish were felling weak and the others killed them !
danios are quite hardy fish i had 4 in my malawi tank for 3 months
hope u get it sorted

Disco Dean
04-30-2008, 09:18 PM
Thanks for all the help - I will see what I can do...


04-30-2008, 10:10 PM
There is no need for an Ammonia remover in your filter. If the tank is cycled, the bacteria take care of the ammonia. I don't think that would cause fish death though. Perhaps step up your water changes to 20% once a week. I assume that the water you add is the same temp, pH and hardness, and you've used a dechlorinator.