I know it do help a lot when us, hobbysts, start a compilation of data about our experiences like this.
But for science, it cant be taken so serious because its kinda random stuff. As aquanero said, there are lots of variables involved.
Just because my ocellaris get HITH, as hullons ocellaris did, and we have 7.4 pH, withouth using almond leaves, we cant conclude 100% that the HITH was caused by non black water (no tanins + humic acid).
Our water have different compositions, we do different treatments to the aquarium, we feed our fish differently. See how you cant be 100% sure about anything?
I know here nobody intends to be a scientist, but I see lots of people with deep theorical knowledge, much more than me to be honest, like aquanero, RD. And thats why Im writting this.
I think the only real way to know this is by simple scientific methodology. Unfortunately I dont see any work with Cichla coming, principally for Cichla as a aquarium fish with HITH. Which is very sad, for me there are few things worst than losing a fish dont knowing exactly what to do even after researching a lot.
But ur guys compilating these data will be very helpful, because lots of hypothesis are being born here, this topic is the living proof of it.
Who knows if some day, one of us taking hold of all those ideas and hypothesis can test them applying scientific method. This would be what I call taking hobby to the next level. =p
And hope you guys dont mind if I take it to serious, but I was teached to think like this.