Black Sand and SPS - No Bueno

[jda123]

So I added a little frag tank to my system and put a 30lb bag of black sand in it... mostly since I had it. This sand is magnetic and would stick to all of my magnets. After 3-4 months of my SPS getting browner and browner, I put 2 and 2 together and replaced it with some typical aragonite. It has been 2 weeks and a water change and most of the SPS are nearly back to normal. Everything else, softies, LPS and clams were totally fine, so take this for what it is worth using the magnetic black sand with SPS.

 

[scchase]

Makes perfect sense, since its magnetic it means it has iron in it, iron is one of the principle limiting factors for algea growth in many aquariums, add a little iron the algea in your corals does much better and they turn brown. Well at least that is the simple explanation.

 

[SkyShark]

This is all theoretical, but what about less light getting to your sps corals from the black sand? Think that could have an effect? I imagine that white sand/aragonite will reflect more of the light to the bottom and sides of the coral and black sand will absorb more of the light.

 

[TheRealChrisBrown]

I have black sand, but it's not magnetic? I wonder if it is different brands or something. The only life directly touching the sand are my two tube anemones and a clam. The rest of my corals are on LR and doing fine.

 

[jda123]

I guess that nearly the same things happens with the magnets on cheap powerheads start to corrode after the expoy breaks down...