Reef Discussion

[Ben Daley]

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?

 

[ReeferRob]

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.

 

[Ben Daley]

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...

 

[ReeferRob]

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...

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.

 

[Mattres]

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?

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.

 

[Ben Daley]

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.

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.

 

[ReeferRob]

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.

 

[Ben Daley]

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"?

 

[ReeferRob]

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.

 

[Mattres]

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.

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.

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.

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

 

[Franklin Dattein]

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.

 

[Mattres]

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.

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.

 

[Jacques Pels]

Hi All,
I have been following this thread, as in my new 3500 ltr set up
I used the RRR. I had always used real LR, but was assured that using this is just as good, without the 'risks' associated with LR. Doing he aquscape, I had to drill into and break off a few pieces, and noted the same - very dense, nearly cement-like interior, and it made me wonder , as you, about the space available for bacteria, like in real LR.
But, as they say, you cannot be half way pregnant, so I have what I have, and can only hope it pans out.

Add to that, the fact that I went out on a limb and added 2 pieces of Drift wood, mainly because of the drop off, or step down which would have been a big empty space. Long debates on how to build a 'ledge' that could be cantilevered over the drop off, without being able to include any reinforcing, so driftwood it was. Tank as been wet for 4 weeks now. Water was yellow from day one, but waited for it to settle. Never did. We did a 60% water change last week. It made the water a lot clearer, but a slight yellow tint remained. The water itself is clean, but the yellow must be desolved tannin from the wood. We agreed we will give it another 2 weeks, so a week now to go, but it looks like it will need to be ripped out, and that will be a fun job, as I sat in there for days, siliconing the wood down, the siliconed the rocks onto it to make it all secure. The second piece is up the center stand pipes, as a cladding, with some RRR and old coral pieces - not easy to remove without stripping most of the aquascape.
we live and learn

Jac

 

[Franklin Dattein]

That aquascape looks really good. Unfortunately, wood in saltwater is a no-go, as you already noticed.
If you really want the wood looking, the branches can be coated with translucent epoxy.

 

[Jacques Pels]

Franklin,
I never even considered that. I have a Plan b in place, at least for the cantilevered ledge - joined several of the RRR rocks I still had together, with fiberglass rods bored between them, and silicon, to end up with a decent looking ledge of about 600mm, so a possible replacement for the driftwood. Only issue will be that I will need to anchor it well, so some of the rock will need to be cut loose and re-siliconed.
For the smaller piece up the stand pipes, the epoxy is an option, rather than stripping most of the rock cladding around the stand pipes.
Both pieces however, will need to be dry, so we will need to empty about 2500 Lt .
Would you know which epoxy is safe and how long it needs to cure before water can be filled again ?

Jac

 

[Franklin Dattein]

Hey Jac,
I am not sure of any brands of translucent Epoxy, as I only time I used it was more than 10y ago. It would have to be those that come in 2L for such large pieces.

My basic understanding of chemistry - which you shouldn't rely on - tells me that most epoxy glues are reef safe, because once cured it doesn't react to water. Their full cure is usually 72hs at the most and waiting twice the time prescribed by the manufacturer is usually safe.
If you go ahead, I would suggest you take a photo of the epoxy composition and post on the Chemistry forum of R22, for some more accurate advice.

Anyway, I wouldn't bother coating it because eventually those branches will get covered in algae or coralline. Your current solution with rods sounds more adequate.

 

[Jacques Pels]

Franklin,
thanks. I agreed to give 2 weeks, to see if it has stopped leaching. It has been a week now since the 60% water change, and it has started to get yellow again. The more I see, read an ask, the more I am convinced it was a mistake, and best to bite the bullet, and nip it in the bud, even it will be a bugger of a job - better now, than 6 months down the road, with corals to displace etc.

If this is going to happen, then I best address the next issue at the same time, since I will nee to dump ca. 2500 lts of water.
I used the Real Reef rock, instead of Live Rock. I have doubts about its composition, as it looks too dense, compared to the section of LR.
Too late to trash all 150 KG of the reef rock, so am thinking to get some real LR and use it to fill in the sections I will need to cut out with the driftwood.... maybe 30~40 KG .
Dropped by Reef Secrets this morning, but they dont have any LR, and can only get it on order.

I am itching to pull the trigger and make the decision on lights, but will post it on a separate mail.

Jac

 

[ReeferRob]

The yellow water is the tannins escaping from the wood. That's a good thing in a freshwater tank, NOT a good thing in a saltwater aquarium.

 

[Jacques Pels]

Rob, '
agreed. I had my doubts, and it was bounced back and forth for 2 months, but in the end I agreed to give it a shot... not a good call I think.
The thing is now to plan he solution - got plan B ready with 7 pieces of the Reef Rock siliconed and pinned with fiberglass rods, to make a piece about 800mm long now.
Will need to plan to have new salt water ready in the IBCs, then dump ca. 2500 lts, expose the driftwood ledge and piece up the stand pipes. Cutting them out will mean, cutting many pieces of the rock also, and re-siliconing them. Then re-fill. Am trying o get 30~40 KG of the real macoy LR to replace pieces removed, and to seed the rest.
While I try to schedule D-Day, the water has settled, even if a bit yellow, with Am way down, Nitrite and Nitrate nearly zero :cool:
The diatom are in full bloom, covering most of the sand bed and rocks.... of course, some hairy strands forming on the driftwood branches. :mad:

Had the 3 Chromis and 3 PJ Cardinals in Q for 3 weeks, and moved them to the MT last week - happy as Larry...so far.

Itching to pull the trigger on selction on lights, and then soon be able to introduce my first corals..!!
I am sure this is all old hat for you guys, but this is a real virgin tank, so I really need to discipline myself not to rush forward, after being so patient this far... not easy.

Jac

 

[ReeferRob]

If you have your heart set on some sort of wood, mangroves are about the only wood I would say would be safe. There's a guy here in the states with a 4'x4'x20" tank as a mangrove biotope.