Sand turning black

[Matt Pike]

Does anyone have a idea why my sand is turning black. It seem to only be where the light is directly above. This is in my 280 with 4 fulval 3.0 they run 4 hrs in the morning and 4 hrs at night. Is this some kind of algae?  

Any help appreciated.

Thanks 

[FrozenFins]

You said its where the light is directly above which makes me think its algae. Not a big deal and super easy fix. Just gravel vac it during your next waterchange, or get bottom dwellers for your tank to run past the substrate. Usually works for me!

[Matt Pike]

On 4/17/2022 at 9:35 PM, FrozenFins said:

You said its where the light is directly above which makes me think its algae. Not a big deal and super easy fix. Just gravel vac it during your next waterchange, or get bottom dwellers for your tank to run past the substrate. Usually works for me!

I have some corys that are going in there tanks been setup for 6 months with only couple fish (black ghost knife and albino bicher) about to fully stock it with 

20ish corys

150 tetra not all at once I will have them in QT and add them 20 at a time

Thanks 

 

Edited April 18, 2022 by Matt Pike

[Colu]

Just a word of caution if you add the tetras as your ghost knife   will eat your tetras when he gets bigger and your bicher will eat anything that will fit in his mouth

Edited April 18, 2022 by Colu

[Brandon p]

It’s a mat algae. If the sand turns black under the surface it due to anaerobic conditions. Just mins that there is no oxygen in there. Sand can pack down and can be hard the get icy down there.

[Matt Pike]

On 4/18/2022 at 9:41 AM, Brandon p said:

It’s a mat algae. If the sand turns black under the surface it due to anaerobic conditions. Just mins that there is no oxygen in there. Sand can pack down and can be hard the get icy down there.

It's just the top layer of sand. It's not compacted at all. Have tons of oxygen also. 2 huge air stones.

[Tihshho]

Anerobic bacteria growth in sand doesn't have anything to do with the O2 conditions in the water. The problem is that the substrate grain size is so small that it's not allowing oxygenated water to flow through meaning that it's an ideal area for anerobic bacteria to grow.

[Matt Pike]

On 4/28/2022 at 8:56 AM, Tihshho said:

Anerobic bacteria growth in sand doesn't have anything to do with the O2 conditions in the water. The problem is that the substrate grain size is so small that it's not allowing oxygenated water to flow through meaning that it's an ideal area for anerobic bacteria to grow.

I understand that this is pool filter sand grain size is not small at all and I have this any other tanks no issue. Wouldn't all the substrate have this problem and not the top layer wich is getting plenty of flow?  Thanks

[Brandon p]

I know this is not wahT you have in your tank but many people do see this. Is is caused by lack of oxygen and sulfur adds fill these pores. Then sulfur eating bacteria set in eat the sulfur. It makes it hard for plants to grow through this. This one of the negatives of sand that is to small

[Matt Pike]

On 4/29/2022 at 12:49 PM, Brandon p said:

I know this is not wahT you have in your tank but many people do see this. Is is caused by lack of oxygen and sulfur adds fill these pores. Then sulfur eating bacteria set in eat the sulfur. It makes it hard for plants to grow through this. This one of the negatives of sand that is to small

Yes sir I under standard that completely but mine is not compacted at all this is pool filter sand. I seen play sand compacted like this. 

Thanks