Coagulation of sand

[spyglass]

Hi All,

I am seeing a coagulation (sticking together) of the sand in my tank. The whole layer becomes red colour. Its not the kind of red algae that forms over the top of the sand, they seem to form between the sand particles so much so that i can hold up the whole piece of sand. Even though i "break up" the coagulation by grinding them between my fingers, it forms back after a day or two. Is it algae ? What can i do ?

Attach a not very clear picture here.

[hfabs]

I had the same problem too recently. I was told that the purplish red sand was due probably to low PO4 which caused the diatom to die off, thus exposing the coralline covered sand. What is your PO4 level? I have confirmed this by taking the top layer of purplish red sand and swished it in a container filled with a little tank water. And the purplish layer came off as loose matters, confirming that it's cynobacteria.

To get rid of the purplish slime : Improve the internal flow and aeration in your tank and hopefully it will help in getting rid of the redslime cyno. If it did not go away and continue to grow, you will need to apply the red\slime remover to eradicate them.

Hope the above is useful.

[iskay]

Siphon off top layer and wash and rinse your sand in SW until the algae goes away when their food source is depleted. You must take care not to re-introduce the algae food else this condition will reappear.

[spyglass]

Thanks Guys, will do as you guys have advised. Will see if it comes back after washing the top layer.