any ideas why my fish are dying?

Question

I have several tanks but one is not doin well.
the temp is ok, nitrate, ph etc all ok, feeding a range of foods (always have) i had neons, clown roach, mollies and tetra's. now i only have a few neons and 3 mollies that were born in that tank.
it wasn't overstocked. i did a 25% water change every week.
there is no obvious signs of disease, like spots or rotting scales or anything, they look healthy.
nothing changed in my care routine but they just keep dying on me.
any suggestions would be helpfull, sensible only please x

ammonia's fine, i've always done a 25% water change and itwould be a bit coincidental for all my fish to be old. i'm thinking maybe contamination off my hands? never know so do i need to clean out the whole tank now??

Answer 1

Sounds like you are doing everything right. do you age and dechlor the water before you add it to the tank? I'm thinking you probably do but just in case you don't that might be a good idea. My friend never used dechor and his fish lived forever I don't know how that happened.
Also this is kind of drastic, but , have you ever done a 100% water change or maybe 50%. I'm trying to think of what I would do if I were you.
Aquarium salt I've heard is good for preventing bacteria and fungus. Have you tried any uniodized salt in your tank? My bettas have been doing better since I started putting uniodized salt in their vases. Less deaths.

Stresszyme form good bacteria in new tanks and established tanks. That's about all I can think of right now. I have 2 African dwarf frogs and 17 bettas. I do 100% water changes for all of them. My frogs seem to be doing ok but they are in a 2.5 gallon so that might be different. I wish you good luck with this problem.

Answer 2

1) check Temperature, if its okay.
2) Any fish carrying infection in the past. Incase a fish was carrying some infection in the past & you removed it but didn't leave the aquarium drying for 3 days, its obivious the other fishes are picking the same disease.
3) Is the any type of air pollution around: It can pass through & pollute the water.
4) Use large size of gravel (pebbles) sometimes microscopic pieces of gravel struck inside fish's food tracks.
5) While adding water avoid the water to directly hit the fish's body. As the new water temperature is different from the water inside the aquariam. Many fishes die because of this reason.
6) See that if the aeration is okay.
7) Keep slow moving fishes separate from fast moving fishes.
8) Check if your water is not being treated with chlorine. You can use filter watered to be sure.
9) Change the fish food. DO NOT overfeed your fishes. In majority of cases the fish die because of overfeeding. Feed them only once a day & also as instructed by the fish dealer.
10) Don't keep the tank's light on for longer periods it affects fishes growth.
11) Keep a sucker fish (which cleans the fungus from the glass & toys)
12) Clean water filter at least once a week.
13) A fan running over the tank is not good for fishes.
14) Clean the fish tank & pepples at least once in 4 months. While cleaning thoroughly wash the pepples with salty water along with the tank.
15) Fix a water thermometer in the tank & keep a watch on the temperatural changes. If its very cold then a heater is required. For tropical fishes the ideal temperature required is between 28 to 32 degree cel.

Answer 3

You may have a "rogue fish" in that tank that is attacking or harrassing the others to the point that the stress is killing them. It could be the clown loach (sometimes they can get nasty), watch the tank for a long period with the room lights off and the tank lights on and see if one of them is picking on the others.

I had a tank like that and found that a plecostomus was attacking the others at night while they were at rest near the bottom. Once he was "gone" no more deaths. (I sold him at a fish auction)

Answer 4

If ammonia and nitrite are at 0ppm, nitrates under 40ppm, dechlorinator is used and no major flucuations of pH, GH, KH and temperature then the likely cause of your losses is either stress (something happening near the tank or in the tank) or illness. Any odd or unusual behavior noted from the fish which perished?

pH, KH and GH should be at ideal levels compatible with the type of fish you have.

External toxins may be a factor (any use of pesticides, air freshners, etc near the tank?).

Answer 5

Maybe you are changing the water too often? i dont change mine every week, and I have no probs with mine

Ive got the same fish as you, except I have black khuli loaches not clown loaches.

Is it possible any foreign chemicals have got in? Furniture polish, hairspray etc?

You could try taking a water sample to a specialist aquarium shop to check maybe?

Answer 6

Have you checked the "well" water in your neighborhood? I used to live in an area where the well's around me would kill the fish within an hour when I would get them home no matter what I did so this might be something to check out.

Answer 7

did u remember to put the water conditioner in ?
are some of the fish ph intolerant ? my they require a certain level of ph
when you wash the filters , do rinse them in the old fish water ? you must not rinse it out under the tap water , that will certainly kill them.
try and leave your water changes abit longer like every 3-4 weeks

Answer 8

From what you say I can see only 1 problem;
You may be changing the water too much and thus not allowing the biological stuff to function properly

Answer 9

Different things it could be.

amonia level...airiator needed
something in the gravel...uncoated collored gravel
the glue that was used to put the tank together.
something off of your hand that got into the water.

find a fish care web on google

Answer 10

we had this with one of our tanks, we did a complet tank clean and put a new filter in with a plastic matting/filter under the stones which we changed from a sandy base, they seem fine now and our mollies has just given birth..