Water: ph vs gh

[mooman]

Hey, I need your guys help to settle an arguement that is going on at another forum. There is a very experienced breeder who swears that you should never have to lower ph (below what you can achieve using straight RO water) in order to get apistos to spawn, only TSS and GH matter. Cast your vote.

 

[fishgeek]

i think some of the problem is the difficultly in actually measuring accurately pH of very soft water

by definition there is very little to hold the pH at a stable point and so the pH can swing with what ever limited elements maybe left in the water
for example where i am my tap water is very alkaline and the pH of my r/o tends to read alkaline aswell


andrew

personally i think there is more than just one thing to it(removing buffers with r/o allows the pH to be manipulated much more easily, say with that piece of bog wood, the acid's excreted in urine

 

[Mike Wise]

It is true - if you can get your R/O water down to pH 4. There are some blackwater species (e.g. A. sp. Miuá & 'Nannacara' adoketa) that will not think about breeding until the water is well below pH 5. I have naturally soft tap water. With peat I get the hardness <1º dGH & dKH, but the pH is still in the 5 range. I use HCl to drop it to about pH 3.8 for these fish.