Adding Dry Rock to Established System

Trouble1375 · Jan 20, 2021

We have a 125 gallon display and a dual sump system adding another 30 gallons of water capacity. Tank has about 80lbs of live sand and 80 lbs of live rock that has been up and running for 2 years but it looked bare and we wanted to create more of an aquascape so we bought 60 lbs of completely dry rock. Reef Rock 2.1 is what it was called. We heavily rinsed it and put it in garbage can with salt water about a week ago with heater and pump to circulate the water and added filters from our display tank. Adding Microbactr7 daily. Testing today resulted in Ammonia 0, Nitrite 0, Nitrate 0 and Phosphate .11. How long should we continue cycling in the garbage can before we add to the tank without an issue? We had an odd run of bad luck in the first 6 months or so with the tank and we finally have a healthy stock of CUC, fish and corals and we don’t want to kill or stress anyone out. My stress is enough.

brandon429 · Jan 20, 2021

it doesn't matter if you add it cycled or not, its not bringing bad things into the tank either way. the current live rock will handle as many fish as you can ever keep in that tank, these new bacteria are simple extras that wont be put to use.

add it now if you like. if you were swapping out rocks that would be different.

some dry rock setups leach phosphate but that has nothing to do with cycling, it doesn't matter here if the rock is cycled or not as the current load of live rock is such a powerful filter, you could take on twice as many fish as you have now easily (but the crowding brings disease which would kill em)

mudskipper1 · Jan 20, 2021

Agreed, you can go ahead and add now if you like. As long as the rock is pretty clean (not large pieces of organics), you should be fine. They will go through an ugly stage, but it should be faster than in a tank where all the rock is new, since you have established seed bacteria and coralline. I recently replaced about half of the 10 year old rock in my tank with Marco rock, and didn't lose any corals or see any negative effects. The ugly stage is just about done now, 2.5 months later.

Trouble1375 · Jan 22, 2021

Thank you for the responses. We just added 11 new frags (mostly hammers, frogspawns, duncans) that are now in the rack sitting on the bare side. We are going to give them a week or so to acclimate to our tank then we will disturb them by building the rock work on that side.

Trouble1375 · Feb 12, 2021

Well this seemed to turn into an epic fail. Continued to monitor and add Microbactr7 to the cycling rocks in the can with heater and flow. Continued to get the same testing as above. Added to our tank on 2/6/2021 and now all the corals are closed up and phosphates spiked to 0.4. Have lost a toadstool and xenia so far. Everything else is closed and/or ticked off. The new rocks have started to grow some yucky brown algae on them. On a positive note - the fish love all the new caves and hideaways.