Dead fish... Ph problem?

[DieselsFish]

I've had 5 fish die recently, and it's a mystery to me.

I tested my tank earlier today and it had 0 ammonia, 0 nitrites, 20 nitrates, a Ph of 7.6 and a temp of 74.

It's a 60 gallon community tank with molly's, angelfish, red-eye tetras, bala sharks, neon tetras, gouramis, siamese suckerfish, a couple frogs, a couple snails and a betta. It's a newer tank so the 25 fish are all pretty small. The biggest fish is probably a 3 inch bala. I have 5 real plants and a bunch of fake ones in it.

The tank has been setup for 3 months or so... it's definitely cycled. I'm using activated carbon... not sure what brand of filter, but the box said it was good enough for 60 gallons. I've only done a couple pwc's since it cycled, and I usually change about 12 gallons and vacuum about a third of the gravel.

An angelfish died a week ago, I ran all the tests and everything looked great except the Ph a little high at 7.6. Then another Angelfish died yesterday, so I ran all the tests and guessed that the Ph was too high at 7.6. I added some "Ph Down" and lowered it to 7.4. Since I lowered it this afternoon, 2 angelfish and a neon have died, and it looks like another neon is about to join his buddy.

Any ideas what could be killing them?

 

[theotheragentm]

Messing with the pH is likely to cause more problems for the other fish. Stable is the key to look for, not necessarily perfect. What is you pH from the tap normally? Was anything new added to the tank recently?

 

[Fishyfanatic]

Stop adding the chemicals. It is only causing harm. 7.6 is fine for your stock. Stable is better than "perfect".

Do any of the fish have white spots? are they gasping for air? Are they eating like normal? What makes you think the other neon is about to die? Any new additions to the tank?

BTW, I wouldn't mix neons with Angels. Neons are a natural food source for Angels.

 

[An t-iasg]

I agree with theotheragentm. The pH down product isn't necessary. All your fish will be fine at a pH of 7.6. The pH down product is a type of acid and I imagine you're using a good bit in a 60 gallon tank. It may be burning the fish's gills. I used to worry about pH too when I first started out. Since then I have had tanks with a pH of 7.8 to 8.0 and as low as 6.6 (with CO2 added) and my fish have been fine. theotheragentm is right; it's the stability of the pH value that's more important to the fish, and causing swings with the pH down product is not good. As you've seen, it lowers the pH for a while and then it bounces back up again.

I would do 12 gallon water changes with gravel vacs (1/3 to 1/2 of the tank at each change) every week. Do you have a python?

Another thought: Your neon tetras may be vanishing because your angelfish is eating them. Neons are angel's natural food in the wild. I know you said the angels died (sorry ) but even in a large tank, I wouldn't mix angels and neons.

 

[DieselsFish]

I woke up this morning to a dead red-eye and a dead neon. The neon was at the top gasping last night, the red-eye seemed fine last night. There's no spots or any sign of illness. A couple fish have frayed fins, but 90% of the fish look perfectly healthy. I haven't added any fish recently... (I added one angel about two weeks ago. It lived for a week and it was the first to die)

This sucks! 25% of my fish have died in the last few days!

I'm not sure what a python is... so I assume I don't have one. My tap Ph is 8.0

 

[theotheragentm]

A Python is an invaluable tool that hooks up to a sink faucet and will create a vacuum to pull water from the tank. It will also allow you to fill from the sink very easily. Makes water changes so easy.

Is your tap pH measured right away or after 24 hours? Let it sit for 24 hours before measuring it.

 

[Zagz]

Do you have an airstone in the tank? If not get one or lower the level of the water a bit to create more splash. What kind of test kit are you using, strips or liquid? What temp is the water at?

Do a water change as suggested and stop the chemicals. The fluctuating ph will cause more harm than good. Did you clean any of your filters recently or add anything else to the tank you haven't mentioned?

 

[DieselsFish]

I think I found the problem... The filter intake tube didn't come with any sort of screen or mesh to stop plants and fish from getting sucked up into it, and I lost a couple fish to it when I first set the tank up. So I MacGyvered some paper clips into a mesh screen to still let small things through but block big leaves and fish from getting through. The paper clips broke a couple days ago, so I tried to find a more permanent solution. I bought a sponge from the grocery store and cut a piece to fit around the intake. I just now looked at the package of the sponge and it says "Not for aquarium use" in tiny lettering. So it must have harmful chemicals in the sponge, which has been poisoning the fish.

So I figure my best course of action now would be to do several water changes to try to remove whatever chemicals the sponge has polluted the tank with.

I know I should only do 20-25% at a time... should I do that amount daily, weekly, a couple times a day?

To answer your questions Zagz, I have two airstones setup, and use liquid tests from Aquarium Pharmaceuticals. Do you prefer strips or liquid?

Thanks to everyone on here for your help.

 

[theotheragentm]

Liquid tests are preferred by most people here in these forums. Buy a filter sponge and make a slit in it. Put it over the filter intake tube.

 

[DieselsFish]

Thanks agentm... I've got a vial of tap water sitting on my desk that I'll test tomorrow to find the real Ph.

 

[Fishyfanatic]

You are safe to do a large water change. I'd bump that up to a 75%. It is going to be less stress on the fish to have a larger water chaneg than to be consuming poison. I do 50% weekly on my tanks and have never had an adverse reaction from any of the fish. Keep doing water changes to get the chemical out of the tank.

 

[rkilling1]

I agree that a LARGE PWC in is order. I would also run some carbon in your filter as well. The PWC will dilute the chemicals and the carbon will remove some of it.

And as mentioned, the Python is a GREAT tool for PWC's. I highly suggest you look into it.

 

[Zagz]

I too prefer liquid tests. Do a 75% pwc. I had a recent run of dead fish and the culprit was lack of oxygen in the water I believe. Once I added another airstrip, all was good. That is why I asked.

 

[DieselsFish]

I did a pwc last night and another today... All the fish seem to be happy, and no more dead ones!

I let my tap water sit for 24 hours and the ph tested at 8.0. Is that ok for what I have in there?

 

[Zagz]

It is high but the fish will be better with a stable ph of 8.0 than fluctuating ph. If the fish were purchased locally they were most likely acclimated to that ph for a period of time already.