Hi Tom,

I guess the KH could be coming from the substrate? It has to be, I just thought that flourite was pretty inert..........maybe it is coming from the mulm?

What would it take to calibrate the test kit? I have RO water that turns blue as soon as I add one drop of KH solution (the TDS meter reads about 6 for the RO....the unit is not used much and pretty new). I also have 4dKH refernce solution from billionz that the kit reads properly......how much more accurate do we need this kit? If you really want I can test it using a specrotphotometer as long as you supply the wavelength that you want me to read at.......then I can do a standard curve but I don't think the kit is lying.........RO water reads as pretty much 0 and 4dKH reads as 4dKH. This is getting off topic.....to get back on topic...........



To answer your question, no I don't think the tank has any negative issue, I just made an observation now that I am using RO water and would like to know the answer.........inquisitive minds want to know

I started using RO water because I want to be able to contol as many variables as possible with my tanks so I can start doing my own tests. The less variables the better the results. Standard scientific method.

Ken T.