fish keep dying!!

[spatten]

Hello all! .. I have a 29 gal tank with about 10 fish. Its up and running about a month now. Mostly Mollies. I keep the temp at 76, my nitrates are always low and my nitrites are never at 0, but very low also. I have a filter and a heater. Change 30% Water once a week. And test my water often.
The problem is my ph keeps fluctuating and I'm losing 2 to 3 fish a week. I don't know what I'm doing wrong. Please help with any suggestions on how to keep my water stable. Also, at this point I have noticed 2 sick fish. One with a glossy looking eye and tiny white spots on her and another with white around her back fin. I read this could be from fish being in severly bad water.. I'm very lost and need help. Its very discouraging! Ty so much!

 

[mtncrux]

If your PH is changing, you might want to buy a hardness (KH/HG) test kit and check your KH hardness. If it is too low (< 2dKH) it can cause PH to fluctuate. Adding baking soda can raise the KH level (if needed) but you need to test before you try to modify your water harness.

If nitrites are not at 0, it is also possible that you tank is still cycling.

 

[spatten]

Ok. That's definitly a start because the hardness is usually low. I didn't realize that would affect ph. Is there something I can buy to fix the hardness? ... also, can you tell me a little more about the tank cycling? Ty!

 

[Posivated]

Is your tank cycled? What is your ammonia reading at?

 

[spatten]

I don't know what my ammonia level is. My test strips are for ph, nitrate, nitrite, hardness, and alkalinity. Should these things cover it?
As far as cycling goes.. I don't know if its cycled yet. How will I know when it is?

 

[Posivated]

There is an article on here all about cylcing with and without fish. I would read that as soon as you can, also you will need a ammonia test as well. I think most people around here recommend a liquid test kit, I use a API Freshwater master kit and it works well.

 

[mtncrux]

Definitely buy a test kit (preferably a liquid test kit) that tests ammonia.

Here is a good article that will help:

I just learned about cycling but I already have fish. What now?! - Aquarium Advice

Don't worry about the PH too much until you are sure that your ammonia and nitrite levels are 0ppm.