If fish are stressed, its nitrite or ammonia, not pH..
Fix that and don't even check pH til your cycled
Not stressed. Happy and active. Angels fight and bag for food constantly, corys are poking around all the time and are dancing after every water change. Actually last 5 days it is 0 ammonia, 0 nitrites, 0 nitrates.
Do use any fertilizer? Please list everything you add to the water.
Seachem Fluorish and API Leaf Zone weekly, Seachem root tabs under sword and hygro.
You tap is almost pure rain water or your utility has a RO water production facility. With water this soft you will need to use a GH booster. You simply don't have enough calcium and magnesium in he water. Also you don't list what you are using for a fertilizer. You water is so soft that it is probably laking a lot of other nutrients plants and bacteria need. If you are getting plant growth it is because the plants are getting them from your substrate. With your KH so low your PH will not be stable.
Spot on. Rain water. Substrate is plain inert 1-2mm gravel with root tabs under rooted plants.
One mystery left is how I managed to get a forest of Java fern and had angels and corys breeding in my old large tank without any water supplements with the exact same tap water? Never cared for PH until this recent disaster.
If you tank do not have CO2 injection
No CO2 for now as I have weak fluorescent tubes for light. But I am planning to move into a small but nice upgraded 32 gal setup in the next couple of weeks, for which I thought liquid API CO2 booster. Is it going to cause same issues with carbonate rock as real CO2? I think I know where I can get some dolomite, just want to make sure, it's worth the effort.
I'd go for a GH/KH booster you add as liquid/powder.
Yes, I may end up there. I'm sure my local shop stocks Equilibrium. What's left is teaching my other half to use that too, while I'm away. Temperature and de-chlor were a challenge, now THIS.
Bump: Thanks all for the replies. I feel like I am getting out of the woods. My concern now is will I shock the fish when adjusting PH?