Sand turning green

[curviceps]

Hi there, my sand substrate (pool filter sand) is turning green. The tank is in the living room, which unfortunately has too much light from the outside (but the light is diffused through screens).

I suspect it is algae, but what type? Short of relocating the tank, how can I reduce or prevent this from occuring again (after I change some of the sand)? Increase circulation? Will a UV steriliser help?

Please see picture below:

Thanks!

 

[dw1305]

Hi All,
Curviceps, definitely algal, it's a green (Chlorophyta) and will almost certainly spread. Algal spores are every where so changing the sand will only work in the short term, and will stop the biological processes in the substrate biofilm that may help control the problem.

You can reduce the light, green algae needs the same light spectrum and nutrients as other plants (Mosses, Ferns and Angiosperms - higher plants).

My suggestion would be introduce some Malaysian Trumpet Snails to turn the sand over and eat the algae, and more plants, floating ones would be good, I use Salvinia, (but I'm not sure that is available in Australia). Plants will both reduce the light to the substrate and mop up nutrients from the water column.

More filtration and water changes will help, as long as it is water that you are adding is low in nitrates & phosphates.

Personally I don't see any use for UV units, it's true algal cells passing through the unit will be killed, but you'll still have all those fastened to the substrate, and the conditions will still be right for more to grow. The way I look at it is, the majority of filtration in their tank is biological, therefore why would you want to kill a small random proportion of it as it flows past the UV unit? If you're using it for "green water", you're treating the symptom not the problem.

cheers Darrel

 

[dw1305]

How is your algae?

Hi Curviceps,
What happened with your algae?
Any update welcome.
cheers Darrel