Friend or foe

[ndewys]

Black sponge like object on my zoa rock could someone tell me what it is and if it’s bad for my tank

 

[DJF]

Yep black sponge… can be invasive. If you can siphon it out you can knock it back; if you can remove the rock you can put rodi on it and it’ll melt and you can scrub it off- careful in tank treating it as you could spread it elsewhere.

 

[moldos]

Yep black sponge… can be invasive. If you can siphon it out you can knock it back; if you can remove the rock you can put rodi on it and it’ll melt and you can scrub it off- careful in tank treating it as you could spread it elsewhere.

wait how can the sponge be bad like what can it do

 

[DJF]

wait how can the sponge be bad like what can it do

Smother the zoas

 

[moldos]

Smother the zoas

fair enough, how fast do sponges grow in reef tanks though? i thought they needed alot of silicates

 

[ISpeakForTheSeas]

fair enough, how fast do sponges grow in reef tanks though? i thought they needed alot of silicates

A lot of sponges struggle in our tanks - a few invasive ones don't. Out of those few invasive ones, a few are harmful to corals.

As far as silicates go, most sponges do need them, but the invasive ones don't seem to struggle with being limited by silicates (it may just be because of the tanks they're in being high in silicates though).