pH levels 6.0 or less, losing fish?

Please help. I don't know what is going on in my tank, I had issues a few weeks back with a sick gourami and I added some meds to the tank which may or may not have been the cause of my pH crash because I honestly didn't test it for a few weeks before that because everyone was "happy."

Sick fish, test water, everything was fine, but I can't remember if I tested pH at that point. Added meds, first tried melafix with no luck, then maracyn a few days later still no luck, fish died. Test pH 6.0...

Did several small water changes over the course of a day or so to not shock them with a high pH change, got pH up to 6.8 with my tap water. After 24 hours or less even, it was back to 6.0... and that has been the story of what I've been dealing with for the last 2 weeks.

I bring it up with a water change only for it to drop after a few hours. How do I increase the buffer? I tried added another air stone and my fish got bubbles all over him (gas bubble disease?) so I had to turn it off. I tried adding coral, fertilizer for plants, leaving lights off. Nothing is working. I have lost 3 fish now, I'm very concerned. Please help.

Other parameters read fine. ammonia 0, nitrite 0, nitrate 5

 

You can also try crushed eggshells or seashells to increase pH, you can put them in the foot of a clean stocking and put the bag into your filter housing.

Have you replaced the carbon in your filter? If for some reason the meds are affecting the pH, removing them may help.

 

The meds should long be out, nothing new has been added for at least 2 weeks and I have literally done daily water changes of about 10-15 gallons, 2 gallons at a time, taking 3 hours or so a night changing water. But I did change the carbon on Friday as well and will probably replace it again today as I am headed to the store for more supplies after work.

To do the egg shells, do I just rinse a regular egg shell? Which would be better, seashells or egg shells? I assume the LFS would sell seashells?

I don't know what else to do or why the pH won't stabilize. I tested the water from the tap and it's 7.8, ran an air stone in it overnight and it it stayed 7.8 so it's definitely not my tap water.

 

I use a product called Kent PH Stable. It just adds some buffers so your ph remains stable, it doesn't alter it. I recommend it highly. Kensfish carries it & The Aquarium Guys does also.


https://www.kentmarine.com/products/kent-ph-stable-buffer.htm

 

You need to pickup a KH test kit and test your water source. You probably have zero buffering so the pH drops. But test to be sure.

You need to add crushed coral to your filter and substrate. It releases the minerals slowly, so don't expect it to make a difference instantly. You may have to do some fine tuning. Adding little at a time until you get results.

 

Take a water sample to your LFS and ask them to test KH and GH. One or both are very low causing pH swings.

If your tank pH was 6.0, if not lower, and in 3 hours you raised it to 6.8 that alone is enough to kill your fish! Ph should not change more than 0.4 degrees in 24 hours and your water changes change it 0.8+ in just 3 hours.

I see in your profile that you are using AmQuel+. Others have noticed that it can deplete hardness with soft water. I'd try switching to Prime and use just one product to rule this out as a factor.