Expanding a sump, help.

[Azasb]

I have a 55 gal tank, 30 ish lbs. of live rock, and a 10-15 gal sump. The tank is fully cycled. I wanted to expand my sump, double the size. If I do so will there be any adverse effects. On the established part of the sump?

[thegrun]

Changing the sump itself will not cause any problems. If you are adding more live rock to a refugium in the sump the new rock should be cycled in a separate container before adding it to your main system or you risk starting a new cycle and killing livestock with ammonia poisoning.

[Azasb]

Should I add the live rock before or after the bio balls?

[Sethjamto]

I'd leave the bioballs out. If you have enough LR between the tank and sump, it is un-needed.

[thegrun]

+1, skip the bio balls in favor of more live rock.

[kriv4o]

I am having trouble understanding the whole thing here.
On one side I see you wanna double the size of your sump which is awesome.
Then .....are you planning on adding more rock to the existing in the sump, or is your sump using bio-balls and you planing on replacing it with LR ? If so you will have to do the change slowly and remove the bio-balls slowly so your system can still catch up and keep running smoothly. It would be a good idea to cycle your new LR, in a separate container, so there would be less impact on your tank and pets.
If you are planning on using bio-balls as addition to your LR, I'd opt for more LR and not use them at all as someone said already.
GL

[Azasb]

Right now my setup has bio balls in the sump and the live rock in the display tank. I am definitely going to expand, but was unsure of the cocequences. I have more questions now.

1. Why is LR preferred over bio balls?
2. Is it ok to have the LR inside the display tank?
3-a. How do I cure rock in a separate tank?
3-b. In case I can't cure, lack of space, can I buy the LR that has been cured by my local store?

[andy2966]

I think The Bio balls will give you a lot more Nitrates. I have Live rock inside my tank and in my sump. I replaced My bio balls with live rock. I have bought Live rock from my local fish store that was cured. So yes you can do that.

[Azasb]

I think The Bio balls will give you a lot more Nitrates. I have Live rock inside my tank and in my sump. I replaced My bio balls with live rock. I have bought Live rock from my local fish store that was cured. So yes you can do that.

Thanks for the info.

[Nanook]

Right now my setup has bio balls in the sump and the live rock in the display tank. I am definitely going to expand, but was unsure of the cocequences. I have more questions now.

1. Why is LR preferred over bio balls?
2. Is it ok to have the LR inside the display tank?
3-a. How do I cure rock in a separate tank?
3-b. In case I can't cure, lack of space, can I buy the LR that has been cured by my local store?

Liverock has great depth and porosity and actually aids with denitrification. It has great biodiversity and is what made reefkeeping possible in the last 20 years.

To cure in a separate tank, all you need is a water-tight container, good water circulation with powerheads or pumps and temperature between 75-80 degrees. It usually takes 6-8 weeks to cure liverock to where you have zero ammonia and zero nitrIte.

LFS "cured" liverock is not always completely cured, so don't risk your fish/corals by adding without curing first yourself.