Pea Gravel effect on pH

[Zhewitt04]

What are the effects of pea gravel on ph. I have a fairly high ph now living in Indiana. I want to get a substrate that won't raise in any more. I was thinking pea gravel was cheap and looks nice but don't know the effects that it would have on my ph. I have searched this in the forum and found conflicting reports. Please anyone with some information please share. I am also open to alternatives for a substrate but really want a ray someday and don't want to spend a lot of money on sand that cost an arm and a leg.

Thanks

 

[duanes]

When I tried pea gravel years ago, it was generally inert. But it may be different, depending on the rock content where it is mined.
The thing I didn't like about it, was because of the large interstitial spaces between the large grains, detritus, uneaten fish food, and fish feces easily slipped deep between the gravel units, and was hard to vacuum out, becoming a source of extra nitrate, and other unwanted nutrient bio-load.

 

[Zhewitt04]

Does a gravel vacuum work? Wasn't sure if its too small? Would sand be better.

 

[duanes]

I found with any reasonable depth of pea gravel, I could never get the gravel vac into it enough to get the detritus out. The spaces in the gravel, also seemed to create organic debris pockets, where hydrogen sulfide could build up.
I am partial to sand because it keeps detritus on its surface, where it can be easily removed with a gravel vac. And I prefer using a type such as pool filter sand, because it is inert (doesn't alter pH) and is heavy enough to not be easily stirred up, and create problems in filters or pump impellers, such as small, light grained play sand.
I realize some people think having mulm sit on the surface of the substrate, as unsightly.
I see anything that would make me vacuum, and thereby change more water, as a good thing.

 

[DN328]

I use "Mexican black river rock" at the 1" and down to 1/4" black pebbles in my 260G. After my tank had cycled, the ph has stayed stable in my experience. I left a small bag of corals/shells in the sump that in theory was to keep the ph stable too. It didn't hurt so I just left it in there.

I manage to vaccum all the detritus just fine. Also, a little bit of algae does grow on the rock - not too much or out of control, but a little so that it looks a little more natural. My plecos cruise around at night and I think like to munch.