HELP! My pH is dropping and I am losing fish!

[candygrrl]

I'm desperate and I need some help please...

I have a 75 gallon freshwater tank that's almost a year old with rainbows and tetras. I have an AquaClear 500 filter. My ammonia is 0, my nitrate level is 0, and my KH doesn't even register.

My tank has dropped from a normal of about 7.0-7.5 to a 5!! :eek: :eek: I keep doing 25% water changes, which temporarily raises the pH, but it starts to drop again. I've replaced the carbon filter, it doesn't seem to help. I haven't added any new fish or plants, but I have recently gotten some of that black brush algae on my plants and driftwood. I've lost a rainbow and two bloodfin tetras so far over the course of a couple of weeks and one of my celebus rainbows (my favorite) is now swimming the spiral stroke of death :sad :sad

Can anyone tell me what the problem might be and what I can try?? I'm at my wits end here and so sad over my fish...

Candace

[Mulla]

I've recently have a similar problem with you. Where I have absolutely no KH at all out of the tap and of course PH started dropping to around 6.2 (not as bad as your experience).

Fortunately for me it only lasted around 2 weeks and now I'm getting about 2o KH from the tap again.

What I would do as a temp fix is to start adding Baking Soda to your tank to increase KH as well as PH. I'd watch the amount you add VERY carefully. Adding small amounts each time and letting it rest, test your PH + KH and add more if required.

I used that method to increase KH to around 3o and PH of 7.2 during that 2 weeks. Well I have to admit that I was a bit heavy handed as I wasn't happy about a PH of 7.2 but anyway next time I'd know to only use small amounts.

Good luck

[Slappy*McFish]

Your low KH is causing the drop. What you can do is add about a tsp of Baking Soda to the tank at each water change from now on. You should try to aim for a KH of around 3-4...do this slowly so as not to shock the fish with the rapid increase in pH. Just do another 25% water change and add a tsp to the new water. Monitor the levels after a couple of hours. It will take a while for the water chemistry to stabilize. Add more Baking soda if need be @ 1tsp daily until your pH gets to where you want it (6.5-7). After that, 1-2tsp weekly at water change should be enough to maintain your KH. An alternative is to add crushed coral or dolomite to your filter.

[candygrrl]

Thanks Slappy and Mulla. I had just finished a 25% water change before I posted so I added 1 tsp of baking soda and will check again in two hours. Should I refrain from feeding until the pH comes up a bit? Also, is there anything I can do for my poor rainbow? Is there any hope for him now?

[Slappy*McFish]

Your normal feeding routine should be fine. I'm not sure if there is much you can do to quick-fix your fish..just play the waiting game and hope they pull through without contracting a disease.

[Mulla]

I'm sure they'll be alright! <pat on back>

The baking soda actually works pretty quickly so you should see the results pretty soon.

[candygrrl]

Well, I added the baking soda as instructed and the pH went up and seems to have stabilized. I think I will add the crushed coral in a few days. I did lose the rainbow that was already sick, but all the rest seem fine!

Thanks so much for the assistance :bowing: :D