Replacing established rock with dry rock

Arruna · Jan 7, 2021

I have a 150 gal tank that has been up for 3 years. Coralline algae everywhere.
I have a large amount of GSP that I am trying to cut down. So in September of 2020 i took about about... 1/4 or 1/5 of my rock work with GSP on it and sold it to my LSF and got new rock from their live rock section to replace it. My tank was fine.

So now, I want to remove more. Maybe like 1/8 of my rock with GSP on it. I have some old rock from another tank I took down a long time ago. So its dry rock. Can I replace it with no issues to my tank? (I dont want to cycle again) I dont mind it algae grows on it as I have a very fat lawnmower blenny who would be happy to eat it.

I just dont want to crash my tank or force a new cycle as all my fish and coral are doing really well. But the GSP is going wild, and I want to separate it on its own island lol.

Flux Capacitor · Jan 7, 2021

Yup you can replace it no problem. You shouldn’t get any type of cycle at all since your tank is well established, and the dry rock doesn’t have any organics to cause a spike.

melanotaenia · Jan 7, 2021

It is advised that if you plan to replace do it slowly and not all at one time, the dry rock will need time to establish so you may have some algae growth on new rock as it settles in.

Flux Capacitor · Jan 7, 2021

1/8 of his rock would would be a small amount, and I would say that doing that amount at once will be no issue. If it was 1/2 the tank yea maybe going a 1/4 at a time would be advised.

I had to do a tank tear down due to getting an air bubble in one of the seams on my Red Sea, I put all new dry rock in the tank, and put the rock I had in the sump. I didn’t have any issues, and no cycling. If you want to be extra extra careful you could put the rock you’re pulling out in the sump, but I don’t think that’s necessary for the amount you want to change.