[allabouttheplants]

i am doing a diy substrate with peat moss, fish emulsion, kelp meal, mineral clay, and capped with 1.5in of black blasting sand. with kelp meal being relatively high in chlorine, i am unsure how much to add to a 125g long tank. Kelp meal has 3.6% of chlorine per volume.

 

[lochaber]

I'd be pretty hesitant to use either the kelp meal or the fish emulsion. Especially the fish emulsion. That stuff is going to start decomposing immediately, and probably give you a big ammonia spike. Not sure there will be much left of value after the ammonia spike cycles, though.

Aside from that, I have no idea how much to add. The good thing about ionic chlorine is it's really water soluble, so after a couple water changes there won't be much remaining...