Purple Sponge (photosynthetic)

[Privateye]

Mine didn't go quite that wild. It maybe got 7" in diameter in its hayday. I had it isolated at the top of a rock, which was mostly its own doing because it choked-out the zoanthids on the rock. It didn't drop any babies though. It would just spread sideways.

 

[Rob A]

So they can just spread all over the tank from one spot??

It will attach and plate out like in the picture..... that started as a 1 inch piece

I attached a 1 inch piece of sponge to a rock with a rubber band and after a few days it attaches to the rock then I removed the rubber band and shoved the sponge/rock up against the side of the tank where I wanted it to grow. I also did one near the bottom of the tank the same way to see the difference in growth. The lights are off now I will post both pics later. I find babies popping up here and there around my tank I don't know how they got there maybe a fish takes a nip a spits it out and it grows where ever it settles who knows¯\_(ツ)_/¯

 

[DmitryB]

So they can just spread all over the tank from one spot??

It will attach and plate out like in the picture..... that started as a 1 inch piece

I attached a 1 inch piece of sponge to a rock with a rubber band and after a few days it attaches to the rock then I removed the rubber band and shoved the sponge/rock up against the side of the tank where I wanted it to grow. I also did one near the bottom of the tank the same way to see the difference in growth. The lights are off now I will post both pics later. I find babies popping up here and there around my tank I don't know how they got there maybe a fish takes a nip a spits it out and it grows where ever it settles who knows¯\_(ツ)_/¯

Ok that's concerning about them spreading since they seem to be very aggressive!

I ordered a Blue photosynthetic sponge from Tidal Gardens.

 

[Michael Hughes]

I ordered a Blue photosynthetic sponge from Tidal Gardens.

Same!

I wonder if keeping them in lower PAR would help control their spread?