Yeah, the PH in RO water will be pretty low.
It's my understanding that OEBT's like a PH in the range of upper 6's to lower 7's (6.8-7.2 or so)
I've heard of people keeping them in a much higher PH though. I think the big thing with shrimp such as these is stability. Once they are used to your tank they should be fairly hardy and be able to adapt to a higher PH if the parameters stay consistent. If you go with straight RO water and remineralize it you should be okay, you may need to raise the PH slightly, but it shouldn't be too difficult.
If I add the river rock, my pH will be perfectly stable in the high 7s, right now it's stable at 6. I can keep it stable at that point but for whatever reason I can't get to stay higher than that.
Call me stupid, but I really have no idea how to remineralize RO water, how would I go about doing this (or can you point me to a thread of guideline I can read?)
does it stabilize at 6?...if the drop is after you put the water in....something in your tank could be driving the ph down...which is GREAT for shrimps....6 is a lovely ph for your shrimps...as long as it stays at 6 I would worry about it....BUT how are your measuring ph...if it is a drop tester...ph6 is the final color and your ph could be much much lower...
It's a drop tester and I think it bottoms out 6. I have another tester (that I don't know if it has enough liquid in that goes down to 5) and I can check that when I get home from work in a few hours.
I'm going to check my pH again with the other tester when I get home and I'll update with what it says. If it is much lower would you recommend that I adjust my higher (tap) pH, to the pH I know the tank will be at with the rocks?
What I'm trying to ask is, if say the driftwood in the tank (because that's the only thing in the tank that I understand can drive the pH down) is the factor here, and I add river rock which will raise the pH, should I then test what the pH is and then adjust my tap water pH accordingly?
If the tester says it really is 6, just stick with the 6 and the tigers will be fine?