onxy vs flourite

[Jamie]

I've decided to use either onxy or flourite for the 150 i'm about to get. I like the look of the onyx over the flourite but Sea Chem says that the onyx will act as a buffer- hence raising my Ph/Hardness. Does anyone have any light to shed on this, - will I have to settle for the flourite? PS- I wish to add cardnials and rasporas to the tank which like a bit softer water.

[ArkyLady]

I'm using onyx sand in a couple of 10 gallons and I haven't noticed any increase in PH so far. You could also use peat moss to help lower the PH, but I don't really think the onyx sand will affect it enough to make a huge difference. At least it hasn't for me so far. Hopefully others will have more experiences to share!

[Cearbhaill]

I used Onyx sand in my 90g planted tank hoping that it would raise my KH- after two months it might be up half a point, if that. My tap water is KH 2 so any buffering I can get is good.

What is your KH out of the tap?
If it is at all low I wouldn't worry in the least. Unless you are actually planning on breeding tetras (the eggs need specific conditions to successfully hatch) it is not really an issue- the fish themselves adjust fine to most aquarium conditions.
I'd go with whichever color suited me.

[125gJoe]

Originally posted by Cearbhaill
.........the fish themselves adjust fine to most aquarium conditions.
I'd go with whichever color suited me. I agree, I have both. As far as looks, they look equally good when wet! Both types benefit the live planted tank and I don't think the buffering of the Onyx is that strong. What's real nice is that there's no need for a layer of laterite! :cool: