Substrate question

[Biggreenavalanche]

I'm in the process of setting up a 125 gallon North American native tank, a river biotope and will be using a sump with a "coast to coast" overflow, and, a river manifold with dual sponges inside the tank, for filtration...turnover will be in the neighborhood of 800gph total...minimal planting, mainly rock and wood...planting may include hair grass and some moss...

substrate question, what is the purpose of "kitty litter" as a sub-substrate ? and do I need it ? and if so, what kind do I use ?

I was planning on just using a layer of high clay content dirt about an inch deep with a mix of river rock, gravel and sand on top...

would appreciate any advice or comments...thanks...

oh yeah, the occupants will be darters, daces, and two smaller species of sunfish, orange spot and blue spot...

thanks again,

Rich

 

[wvance]

Cat litter contains Laterite. From what I've read, Laterite is a great lower layer substrate for planted tanks bacause it dosent release any minerals and stores nutrients for plants. I'd be careful with the cat litter though as most have perfumes and clumping agents added to them.
Hope this helps...