[angelcraze]

I've always had problems growing Vals. I found out that my kh is too low, or rather co2 is not available, so my vals consume the little bit of KH I have. If I add crushed coral to the filter, I can bring and keep my kh at a 4. The val, then grows fine. Except, without co2, my ph is then 7.6, which is not so ideal for raising krib fry. (fry gender is dependent on ph)

I have removed the crushed coral, and the val has slowed down, but not died. Where should I keep my kh for a happy medium? My logic tells me that the vals will lower my ph. For now, I will not be adding pressurized co2.

This whole thing annoys me because vallisneria is present in the Amazon Basin, (I have a South American tank too) where the ph can go as low 5.5. Guess I can't do vals in a South American tank without co2.

 

[angelcraze]

Plants are growing healthily, but I guess that would depend on many other factors. I am referring to all the plants in that tank, not just vals. My concern right now is just the vals though, and how they use/consume carbonates when not enough co2 is available.

It's not that the vals aren't growing, they have just slowed down. No, I am not sure if it's because of other reasons, the carbonate thing is just what I've been told in other threads.

No, I don't use excel in that tank, I should probably, but I've read that vals don't like that, and my main focus plant-wise was to be successful growing vallisneria.

For the kribs, I've read over and over that an alkaline ph results in more males while an acidic ph results in more females. There is debate as to whether other factors play any role, like temperature for one, but my krib fry are 6 weeks old, and I have yet to see what I end up with. They are hard to sex at this age, at least I cannot be sure at all, but I tested my ph (not kh) yesterday and was still at 7.6. So I will see I guess in a few more weeks. The temp is at 80F.

In general, I was never concerned with ph, just monitored kh, but a visit to the LFS resulted in an impulsive decision and now I have krib fry. I read about the ph thing after the fact, so I really have no personal experience to base this theory on.