KH and Cards

[Soothing Shrimp]

I'm confused.  If ph swings are bad for shrimp, why is low or no KH encouraged for cards?

[danielt]

That's a pretty good question. I'm curious if someone has a good argument.

[Pika]

The only rationalization I have made to myself (and it's pure speculation) is that's "just how it is" where they originate. A natural ecosystem has its own set of checks and balances that might limit any pH swings despite the lack of buffering, and we just have to work at it because we have a limited system.

[wicca32]

that is partly why most use a buffering substrate. with a kh of 0 with out the substrate the ph would be all over the place. when i had crs i had them in a kh of 2 and used tap water and they did fine. with my kh at 2 it never had swings so i wonder how much of a swing you would get with kh 1?

[featherblue]

My tap has a kh of 1 (2 sometimes), snails could live and my ph bounced a2 days after wc. I add alk (from the sw section) to my pre water change bucket to keep my neos at 5-6 dkh and a stable ph of 7

[Pika]

that is partly why most use a buffering substrate. with a kh of 0 with out the substrate the ph would be all over the place. when i had crs i had them in a kh of 2 and used tap water and they did fine. with my kh at 2 it never had swings so i wonder how much of a swing you would get with kh 1?

So the buffering substrate must use buffers other than carbonate, I'm guessing? (chemistry was oh-so-long ago...)

[Subtletanks91]

I would assume the buffering component to the substrate have more to do with the clay (speculation on breaking the granules apart) and where it's from and how the substrate are held together.

Are the materials used to make the substrate from river banks I. Foreign countries were ial, alder come, oak etc have been broken down and solidified and then harvested with the material creating the buffering effect in our tanks????

[danielt]

I do believe pH swings kill by the ammonia route. Poor water circulation + poor filtration + pH swing can cause a deadly ammonia(NH3) spike which otherwise stays in the ammonium(NH4) form if your pH value remains in the acidic range (<7).