Making changes-Need your input

[pschom]

I have a very established and fully stocked tank. I can't kick the cyano and I have an algae infestation that has taken over and is wrecking the corals. Been going on for a while...

 

I'd like to change out the sand and most of the rock without causing a massive cycle and killing stuff (especially the carpet nem!). I have the rock replacement and it will be taking a bath here shortly. I'll probably take a non-algae covered rock and take a toothbrush and some chems to it to clear the pest alge-then use that to seed the dry rock in a tub for a while. Was thinking about seeding it with some pods as well.

 

I also want to change the sand out to try and get rid of the cyano issue. Also I'll probably start a small algae scrubber / fuge in the sump area with macros in order to keep them from the display.

 

How can I do all this without creating a cycle that will kill everything? Changing out the rock is easy, just takes time. Deleting rock slowly and then adding the new rock over the course of a month shouldn't be an issue IMO. But the sand...??

 

What am I missing and what r ur thoughts?

[jedimasterben]

You sure that your sandbed is the root cause of your issues? Cyano typically rears its head when there is a nitrate/phosphate imbalance. Try removing or increase phosphate remover use.

If you insist on removing your sandbed, just siphon it all out. You'll pull out a lot of water, and either replace all of it with new saltwater or put the water back into the tank, running it through a 1 micron filter sock (or two stacked), and then use a flocculent to bind together anything that was missed and your protein skimmer will pull it out then. You can also just leave it in the tank and use Seachem Prime or Aquavitro Alpha to oxidize some of the organics (really not a bad idea no matter what you do).

 

For the rock, what kind of 'pest algae'? If it is just hair algae, and the rock is removable, take the rock out, spray 3% hydrogen peroxide on it, let it sit for a couple of minutes, rinse it off in a bucket with a little saltwater (very important step!), and put it back into the tank. The algae will die and your cleanup crew will take care of it.

 

Alternatively, just get some Mexican turbo snails, they'll make quick work of most semi-complex macroalgaes.