General Live Rock Vs "real Reef Rock"?

Discussion in 'General Reef Related Discussion' started by Ben Daley, Dec 24, 2017.

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  1. Ben Daley

    Ben Daley /dev/null

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    Quick question regarding "real reef rock" (eg. the brand name of one type of fake, man-made rock):

    When broken, this stuff seems very dense.
    Would it be reasonable to presume that actual live rock (or dry live rock) would provide better conditions for denitrifying bacteria?
  2. ReeferRob

    ReeferRob Solidarité

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    Every time I've used that "Real Reef" rock I have had hair algae issues. I only use real live rock, freshly collected. Yes you can get hitchhikers, but the end result is better in my opinion. No waiting for the tank to go through a prolonged cycle and there's some damn cool stuff that grows out of the rock.
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  3. Ben Daley

    Ben Daley /dev/null

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    Interesting. To date I've only set up 2 tanks (>90% RRR both times) and have had issues with nitrates and unbalanced alk depletion in both.
    I was reading an article recently that suggested excess alkalinity depletion can be a side effect of an incomplete nitrogen cycle.
    I'm thinking I will pull the trigger and order a couple of boxes of fresh LR from Cairns Marine and as it cures swap out the RRR in the display.

    On a side note, is good LR hard to come by in the US? I was looking at a few sites there and it looked either very lack lustre, or very expensive...
  4. ReeferRob

    ReeferRob Solidarité

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    It's very easy to come by right now Ben, but it's quite expensive, about $20-$30/kg for good Indo live rock and about the same for Fiji when it was available. Florida aquacultured rock is about $6-$7/kg. The Florida rock is LOADED with all kinds of mantis shrimps as well as chicken liver sponges that die off. I only use Indonesian live rock in my tanks. I did get some Fiji in a few weeks ago that I'm going to hold onto until they figure out what the hell they're doing over there.

    The biggest issue with the man made live rock is there isn't enough open spaces in it for denitrification to take place which is why I don't use it. The same is true of the Tonga branch rock, no place inside the rock for bacteria to colonize.

    I'd kill for 100-200kg of Aussie live rock to try out. I throw mine into one of the empty quarantine systems with my baby Titan trigger (He's 36cm long) and a Hoeven's wrasse to dispatch any mantis that make the trip and quite a few do. I know a 1500l system probably isn't an option, but that's how I keep the nasties at bay. I wait a week before I send in The Rangers to get all of the desirable things out like urchins and small shrimps.
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  5. Mattres

    Mattres Member

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    When I set up my 120 and used all “RRR” I actually thought the same thing, seemed very dense. But I thought it may actually increase the denitrifying bacteria as there would be less oxygen.. However for a while I’ve been thinking along the lines that this rock is.. well crap. Be it the actual rock itself or just the fact it’s starting from ground up to create an ecosystem but either way I’ve never had so much trouble starting a reef.
    Did you use all real reef rock when you started your tanks?
    I feel like my tank has gone through a 7 month cycle with no end in sight.
  6. Ben Daley

    Ben Daley /dev/null

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    Yes, I started both of my tanks with close to all RRR (a couple of small pieces of LR to "seed" it).

    My first tank (200L, 6 small fish + 1 large mantis) took about 9 months to settle in. The second tank (400L, 20 small fish) was much better (~6 weeks).
    I restarted the 200L back in October and used about 50/50 RRR and LR. It is doing much better than first time around. Admittedly the bioload is lower (1 coral beauty + 1 six line wrasse) but all the equipment is the same.

    I suspect that even if the density of RRR does (in theory) create a good anaerobic habitat, there would be issues with getting water in and out. However I think it's more likely that the dense interior is essentially just dead cement and always will be... or "crap" as you so eloquently put it :D

    On a brighter note, today I got a 120L tub ready to cure the new LR. I'm going to do it - will let you know if it makes a difference.
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  7. ReeferRob

    ReeferRob Solidarité

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    I wouldn't say it's crap, it is what it is. I think it would be great in an African cichlid biotope, but not a reef system. Mother nature has been working on this system for billions of years and she's done a bang up job. It needs a lot more voids for colonization and a whole lot less density. If you're going to use this you're going to need some other form of biological filtration suck as Siporax or Marinepur media for denitrification. I personally think this is where people go wrong, not having enough denitrification. I've been slowly adding it to several systems and watching the effects. You want quite a bit of bacterial colonization space, just not so much that you're stripping everything out of the water column starving the rest of the life in the tank. Corals use a bit of nitrates and phosphates. We're on a steep learning curve here, we'll figure out something one day, hopefully in the not too distant future.
  8. Ben Daley

    Ben Daley /dev/null

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    Cheers for the info Rob, IIRC I paid $18-$27 AUD per kg of RRR so $20-$30 for good LR sounds comparable.
    Paying for RRR that has been shipped instead of the cheaper local LR is clearly doing it wrong!
    Unfortunately a 1500L system is out of the question right now. That might change in a couple of years...
    PS. Who are "The Rangers"?
  9. ReeferRob

    ReeferRob Solidarité

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    US Army Rangers, I was a Ranger from 1980-1989, then again for GW1.

    Your 120l tub should be good for curing it out. i keep mine dark for 2 days, but keep the water moving as much as you can and get anything dead/dying off the rock and out of the tub ASAP . If you don't, it gets real stinky real fast. Back in the 90s when we had our shop we were bringing in 200+ kg of rock a week. It would get stinky in the shop for a day or 2, then it smelled like the ocean in there. Keep it as open as possible to allow the flow to flush out anything in there. You'll be surprised at what will grow out of that rock even though it looks like it's barren will surprise you.
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  10. Mattres

    Mattres Member

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    Yea i think you're right on the money with the density situation.
    Awesome, definitely keep us up to date on how the new LR goes in the system once introduced. I might go down this road when i can find the time.


    Yea your right, there's nothing better than what mother nature has been building herself.
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  11. Franklin Dattein

    Franklin Dattein Member

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    Real Reef Rock and any other man made rock for aquarium works great for what it is designed, as long as you understand the trade-offs involved.
    Surface area provided by Live Rock and Sandbed is no longer crucial in moderns reefing techniques. The problem can easily be overcome by adding surface media - such as Siporax - to the sump and Organic Carbon Dosing, to promote bacterial activity directly in the water column.
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  12. Mattres

    Mattres Member

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    I agree and im starting to learn the tradeoffs now. I did however start my new tank with the siporax from my old system which should have provided all the bacterial activity for the small amount of stock in the tank.

    @Ben Daley I did a small test yesterday on the RRR. BRS did a video comparing rocks they sell (Pukani, Fiji, Tonga and Reef Saver) They tested them by taking a 1kg sample of each rock, soaking them overnight and weighing them again to find the amount of water they would hold.
    The results were:
    Pukani held 380grams of water
    Fiji 210grams
    Tonga 90grams
    Reef Saver 60grams
    I tested two pieces of RRR just over 1kg and they held almost the exact amount of water averaging 105grams.
    I dont know what the average piece of live rock we get here in aus would hold but going off the rocks BRS tested the RRR is well over three times less than the pukani and just half of the fiji.
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