Black spots appearing in sand!

[DeirdreHoyle]

Does anyone know what this is?? I recently switched the substrate in my tank from gravel to sand (there's still some gravel left) and now these spots appeared. I have root tabs in the sand, is that what this is?

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[nkoyko]

What brand of root tabs do you use?

How long have you had the sand and do you stir it up to releases the anaerobic pockets?

It may be the root tabs or you have anaerobic spots in your sand.

 

[DeirdreHoyle]

I just put the sand in last Saturday and I use seachem flourish root tabs. I've done a few water changes but haven't stirred up the sand much. I have snails and kuhli loaches, do they help stir up the sand at all?

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[nkoyko]

I'm going to say it is probably the root tabs. The seachem one's are black and would likely leave that residue as they disintegrate. I haven't used those ones in my white sand so I can't be 100% on that. The API tabs turn my white sand red.

Depends on the snails and I don't know anything about khulis. If you have a burrowing snail then they should aerate for you. MTS are great for aerating sand.

 

[DeirdreHoyle]

Oh I have a ton of MTS, they're great. Also some pond snails. And ok I think it's the root tabs too then, I guess I'm just new to this sand!

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