Hi, I am so confused with what to do it is driving me obsessed. I'm also not sure if this is in the right section.
I have a 40gal. tank with koi fry that had to bring in for the winter. It took 7 weeks to cycle. Now my KH is low and PH is at 6.8-7.0. I would like it higher, usually when I do a water change it will bring it to 7.4 and hold for the week. The day after the water change- it was 6.8-7.0 and the KH was 0. Gh is 5 drops. I have a live rock in there, but it obviously is not doing much anymore. I have researched so much that I can't even comprehend what I read anymore. Everyone keeps telling me if I don't get my KH up, my fish will die. I had an old buffer that I put 1/4 tsp in a bucket of 2 gals. It brought the PH to over 8 and the KH to 5 drops. I am scared to add that to my tank as it is a HUGE difference. Can I put that 2 gals in slow over the day and will it even do anything? I don't want to have PH go up fast and then back down again.
My tap water is GH 2-3 drops, KH 2 drops and PH 7.8-8.0
Why is the tank GH higher than the tap GH? Is that enough minerals for their gill function?
During a search, I saw something called Calcium Reactor Media. Is this something that could keep KH and PH at a good range on a stable basis? Can it be used with only sponge filters and a bare bottom?
Any help would be greatly appreciated as I don't want to kill my fry or stress them anymore than the cycle did.

I have a 40gal. tank with koi fry that had to bring in for the winter. It took 7 weeks to cycle. Now my KH is low and PH is at 6.8-7.0. I would like it higher, usually when I do a water change it will bring it to 7.4 and hold for the week. The day after the water change- it was 6.8-7.0 and the KH was 0. Gh is 5 drops. I have a live rock in there, but it obviously is not doing much anymore. I have researched so much that I can't even comprehend what I read anymore. Everyone keeps telling me if I don't get my KH up, my fish will die. I had an old buffer that I put 1/4 tsp in a bucket of 2 gals. It brought the PH to over 8 and the KH to 5 drops. I am scared to add that to my tank as it is a HUGE difference. Can I put that 2 gals in slow over the day and will it even do anything? I don't want to have PH go up fast and then back down again.
My tap water is GH 2-3 drops, KH 2 drops and PH 7.8-8.0
Why is the tank GH higher than the tap GH? Is that enough minerals for their gill function?
During a search, I saw something called Calcium Reactor Media. Is this something that could keep KH and PH at a good range on a stable basis? Can it be used with only sponge filters and a bare bottom?
Any help would be greatly appreciated as I don't want to kill my fry or stress them anymore than the cycle did.
