The Planted Tank Forum banner

pH-neutral sand & mineralized soil ???

1552 4
Hi, long time lurker, first time poster here.

Question: Do I need to neutralize the [small amount of] calcium carbonate in coarse sand when I use it in combination with mineralized soil?

I've been reading up on the mineralized soil technique many people here have used with great success and I find it very fascinating and most important of all, cheap and easily accessible. If anyone here has used sand with small amount of calcium carbonate in it, please tell me about your experience, especially with respect to the pH of your aquarium water, assuming you don't have hard water to start with. My local building supply place has the kind of course silica sand of the right size and color and I intend to use it. If necessary, I will neutralize the calcium carbonate with muriatic acid. So, what do you think?
1 - 5 of 5 Posts

·
Registered
Joined
·
21,007 Posts
You can't neutralize calcium carbonate. Acid will dissolve it, so you can wash it out, but if there is any calcium carbonate left it will continue to slowly dissolve in the water and raise the GH and KH. If you plan to use an estimative index dosing method, which requires regular big water changes, a small amount of calcium carbonate won't be a problem. The water changes will keep the amount in the water to a minimum. It is when you only add make up water, over a long period of time, that the KH buildup could become a problem for you.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #3 ·
Thanks, Hoppy. It looks like the sand I want contains very little calcium carbonate because I was able to completely dissolve all the calcium carbonate in one cup of sand using just one cup of vinegar. That's very good new because I can just use vinegar to do that instead of dangerous acid.
 

·
Registered
Joined
·
572 Posts
When you dissolve calcium carbonate it becomes calcium hydroxide in solution. It would be really hard to remove it from the sand completely and as soon as the calcium hydroxide finds CO2, it turns right back to calcium carbonate. I think you'd be better off with water changes personally. I suppose you could try it, but I believe you might run into issues doing that.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #5 ·
Lycosa,
Now that you remind me, I can't use vinegar at all but I have to use HCl then and the CaCl2 is easily washed away, right? any further problem with that? I was never good with Chemistry.
 
1 - 5 of 5 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top