Me again with a Substrate issue.

NanaReefer · Aug 3, 2015

Hi Randy

I'm sure this is chemically related but how so I've no idea. The substrate in my sump/refugium has turned to stone. Hard as a rock, almost. I can break it up with effort.
So I checked my DT substrate as well, it's a finer sand, and found a spot in a corner that is hard but less so than the fuge.
Need I be concerned? Does this need to be corrected?

melypr1985 · Aug 3, 2015

That's very weird! I wanna know what the deal is with that as well!

hig789 · Aug 4, 2015

NanaReefer said:
Hi Randy

I'm sure this is chemically related but how so I've no idea. The substrate in my sump/refugium has turned to stone. Hard as a rock, almost. I can break it up with effort.
So I checked my DT substrate as well, it's a finer sand, and found a spot in a corner that is hard but less so than the fuge.
Need I be concerned? Does this need to be corrected?

You dosing anything? What are your parameters?

Here's a quote from Randy on another forum. I can't find the article where he talks about it.

"The things that usually cause sand clumping are:

1. new sand/aquarium
2. High pH, usually from limewater (kalkwasser)
3. excessive calcium and alkalinity, and perhaps low magnesium

The clumping may be direct precipitation of calcium carbonate between grains, or it may be a bacterially driven process."

NanaReefer · Aug 4, 2015

I dose 2part via doser. Parameters are pretty stable, ALK 8.4, Ca 440, Mag 1360, Ph 8.2, SG 1.025, Temp 80.2
Tank's been running a little over a year. Nothing seems to be affected. However I am using more 2part than seems necessary. To me anyways. 30ml a day of each just to keep the above numbers.

Randy Holmes-Farley · Aug 4, 2015

Some people get that hardened sand (including me when I started my tank).

I don't see any problem with the posted values.

Aside from some creatures that keep the sand mixed, I'm not sure what else you can do.