How to prevent Ph from droping down?

[tanya]

Hello all! My babies swimming with one gill close, they also become dark in color, one died today, he was gasping at the water surface. If it's not gill flukes, I suppose the reason- Ph droped down to 6, as from tap water has7.5Ph.
In my second tank I have 5 adult discus, they also have that problem, Ph droped to 5. I have live plants and bogwood in this tank. Could you tell me, if I am right about Ph? What can I do to prevent this, Do I need to bufer my water somehow? Thank you!

[Aqua Messiah]

Hello Tanya,
It sounds like your water has no buffering capacity, just like mine. There are many options you can choose from to eradicate this problem. Local fish stores will have various buffers to choose from, but they are REALLY expensive to use if you're changing water everyday like I do. I use plain old sodium bicarbonate (arm and hammer baking soda) to buffer the water in both my discus and african tanks. I get it from the co-op for $7 for a 50 pound bag which will last me about a year. The problem with baking soda is that it will try to bring your ph up after you add it( to about 8.2-8.4) so you probably will only need a small amount (start with a teaspoon per 25 gallons). I wouldn't add it straight to your tanks either as your fish are already stressed out. Do you age the water for your water changes? If so, you need to add the buffer into your storage container BEFORE it goes into your tanks while your water ages.
PH is a really tricky thing to figure out and to stay on top of. Discus are extremely sensitive to rapid PH swings, so if your dropped that far then that is the reason your fish aren't doing well. I would get the PH stabilized and give them awhile before you treat with meds (if that was your intention). You will probably find no need for meds once you get your PH right. I would add 1 tblspn of salt per ten gallons and give your babies some time.
I hope my babbling has helped you in some way
Rob