H.O.T. Magnum and Salt-Water Tank

As long as your calcium levels are good the Coralline will grow. If you clean off the diatoms they will just come back. They use the silicates in the water (silicates come from plastic parts, tap water etc.) as soon as all the silicates are gone they will die off.

 

Your tank looks less then a month old. Corraline algae is just calcium, so make sure your calcium levels are around 440-480. Alk levels need to be sufficient to, as well a mag. Sorry to say this but dont expect to see corraline algae spreading for atleast a month, all of this takes time. To speed up the process you could take the rock out and scrub the diatoms away but its a major pain in the you know what, though they probably wont come back depending on your water conditions. Make sure your get lots of astrea snails, stay away from crabs. nassarius snails are great for cleaning up your sand bed they just take time like everything else.

 

Ok, that is what I thought. Yes, the LFS recommended exactly that which is what I did. I got 20 Astreas and 5 Nassarius. I just have two hermit crabs which have been there since I first started up the saltwater tank.

I understand what pgoodsell is saying and it is probably the moon sand that is causing a lot of it. I am digging the uniqueness of the black substrate though and want to make it work. I know it should be a fun headache to work with.

As I want to build a reef anyhow I think I will just scrub the stuff off for now and try and get coralline flakes all over. I do have some calcum and something else the LFS recommended getting to start off with along with level testers for those.

I am going to hit up the LFS and get some putty and maybe a few more live rock for building the reef tonight.

 

I use the same filter for my 20 gallon saltwater tank. I also use ceramic pellets and plastic bio-balls in 1/2 the filter and a carbon pack in the other 1/2 of the filter. Every time I've cleaned the filter (taken apart and cleaned up the glass anemone's and bristle worms out of the filter), I've literally been able to pour out pods from the bottom of the container. Water quality has been fine ever since I've added macroalgae in a breeder net. Really no problems to speak of (make sure the o-ring in the filter is set and you're golden).