Adding more dry rock

Discussion in 'Other Reef Talk' started by James Oh, Dec 7, 2018.

  1. James Oh

    James Oh Supporting Member

    So the 40b I have was meant to be a frag tank but I can't stand to look at the frack holder in the tank. I just hate it lol. So I was thinking about taking out the frag holder and adding 10 more lbs of dry rock. Now I looked around online and a lot of people seems to have different opinions on how this should be conducted. I see some people say you have to cure the rock for months before adding it to the tank and some people just say to rinse it off in RODI and just add it to the tank. Now to be more specific I plan on picking up some of BRS' dry shelf rocks, about 10 lbs, and adding it to a 40B that has a 40g sump. Will 10 lbs of dry rock cause any issues? I do plan to soak it in RODI for a day to get any debris off but I also didn't want to cause some sort of mini cycle or anything in the tank. Currently the tank has 10llbs of dry rock in the DT and the sump has a 8x8x4 marine pure block. Just wanted to take the frag holder out and add some "shelf" rocks in its place. Curious to hear others opinions.
  2. xcaret

    xcaret Guest

    I’d expect the new rock to have a cycle; you can rinse it and would seem “clean” but it’s porous and has to be populated with bacteria, expect something to happen. Keep it cycling in the sump or if you have a separate tank/bucket, you can seed it with small rubble from your tank.
  3. JVU


    If the rock you are getting is man made and not from the ocean, I would not expect it to release decomposition nutrients (aka cycle by some people) and you can add as much as you want.

    Of course it will need to become populated by normal bacteria (another better definition of cycling), which will take time.

    Even if it is "live rock" (has a small amount of decomposing stuff in it), I think if you add a relatively small amounts at a time you will be fine, like 10% increase in rock surface area per week or two. The MP blocks count for much more than their weight in this regard, but not sure how much more.

    You can always just check ammonia/nitrite when you add rocks, and if it bumps up, take the latest new rock out and put in a bucket with tank water and some rubble from the tank for a week, and then reintroduce it.
  4. James Oh

    James Oh Supporting Member

    Yah, I guess I won't chance it and just cycle the rock in a separate bucket. It is a man made rock I believe. (The shelf rocks that BRS sells) I have a couple small cubes of marine pure, i'll probably put those in my sump for a while to use as a seeding mechanism. Then i'll toss those small marine pure blocks in a bucket with the new rocks for a while. Thanks for the info!
  5. rygh

    rygh BOD

    Don't guess!
    With a small tank, the risk is too high.

    Put it in a bucket of water for a week, then test for ammonia and nitrates.
    If either is high, keep treating with water changes in the bucket until they are not.
    It might be great, or it might be a couple of months.

    Note: With really nasty rock, I just use tap water for most of the time, changing it every 3 days,
    and spraying it with a hose each time to clear out rotting detritus.
  6. James Oh

    James Oh Supporting Member

    I'll probably just use rodi just to really make sure I'm not leeching anything into the rock.
  7. Where's the rock from?

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