Question about adding new rocks to an established tank.

[Tommy]

So....I want to make a new rock structure using dry rock and cement, it's going to be a 1 piece big structure to replace all the smaller rocks that I currently have stacked up in the tank.  How can I safely do this without having my tank crashed?  In the sump, I have 2 big Marine Pure square block.  Thanks in advance.  

[paul b]

I don't see why the tank would crash by adding dry rock.  Just add it.

[Big Country]

Just keep an eye on your skimmer, will probably have to adjust it to keep it from overflowing.

[epleeds]

How big is the tank?  Are you replacing all the rock with new dry rock?  If so, you will have a cycle. 

 

Can you soak soak the new dry rock in the tank water for a few weeks before you do the transfer?  Use the water from a water change. 

[Tommy]

The tank is a Red Sea Reefer 250 (65g total volume)  Yes, I will be replacing with all the rocks with new dry rocks.  Yes, I can soak the new rock in tank water for a few weeks.  Thanks 

[Tommy]

Should I soak the rocks in vinegar or something else for a few weeks before soaking it in tank water since it will be bonded with cement? 

[epleeds]

U using Marco mortar or reef putty to bond the rocks?

[Tommy]

Marco mortar.  Thanks Eric! 

[epleeds]

How long has the tank been up and running?  I think you might have an issue with changing out every piece of rock at once. I know you will have an algae bloom and that could cause other issues. 

 

Also so depending on the rock, certain dry rock leaches phosphates so I would be careful on that too since your tank is only about 50 gallons minus the rock. 

Edited March 28, 2019 by epleeds

[Tommy]

Tank been running about 2 years.  Perhaps, I could leave a few pieces of the old rocks in there for along with the new rock structure for a few weeks if it would help.  Thanks.

[epleeds]

Post a pic of the tank as it sits. 

[Tommy]

[WheresTheReef]

You will be taking out live rock and replacing with dead rock. This is where most of your biological filter resides. Can you move some of it to the sump to give your dry rock a chance to grow bacteria? After several weeks remove little by little until it's all gone. What is your current fish load like?

[WheresTheReef]

Looking at your pics your fish load is heavy for that size tank. I think I counted 8 fish. I would be concerned with replacing all the rock at once.

[Tommy]

I have more than 8 fish...most are small  lol.  Yes..I understand it will be a challenge that is why Im asking for advice and to see if the risk involved is worth the reward.  I think Eric is asking to see where the tank sits so possibly I can temporary plummed the tub that would hold the new rock to the tank for a few weeks so I wont have a cycle.  

[epleeds]

Yup. That was one reason. Are you planning on selling all the rock and corals in the tank now, or frag them onto the new rock?

 

plumbing another tub into the system might be an issue with a power outage since that sump wouldn’t be able to hold the additional volume from a holding tub. 

 

The other option which might be better, although not as pretty is to transfer your fish and coral into a Rubbermaid, cycle the new rock in the tank for 30-60 days and then start transferring back into the tank. 

 

That way the tank can cycle properly and you and you don’t loose anything since that has all be moved to the tub. 

[Tommy]

I am transferring all my corals to the new rocks, they are easy to remove as they’re on frag plugs and such. I think I will just let the rock cycle in the tub for a while with some of the old rocks. Thank you so much !