Reef Discussion

Ben Daley

/dev/null
Dec 23, 2016
162
101
Melbourne
Curing Live Rock (and Failing)
Last week I received 35kg of fresh LR and set it up in a 120L tub to cure.
I've never done this before and think I may have killed it :(
  • First day, did not smell bad (like low-tide with a slight hint of decay)
  • Second day, rotten egg smell, removed about a cup of sponges that I had missed from the previous day
  • Third day the external temp hit 40℃. I expect the water temp reached 30-32℃+. TERRIBLE smell. Loads of worms floating about. Dead oysters. Large tunicate appears alive.
  • Fourth day, another 40℃. Equally bad smell. Black water
  • Today, black water and black/grey rocks, dead tunicate. No signs of any worms or other inverts. Slightly better smell, but still foul. Some coralline appears to be hanging in there.
I don't have a skimmer to run on the tub so intended to compensate by performing more water changes.
I have performed a 100% WC every day given the stench. The rock is exposed to air for 10 or so mins while doing the WC, is this making things worse?

I fear that missing some of the sponges on the first day really fouled the water and caused a lot more die-off... then the hot weather finished the job.

Is any of this normal?
Is this rock dead or will things still grow out once the cure is done?
 

Savage Henry

Member
Feb 2, 2015
653
254
Well, if you wanted to ensure any pests present have died then I'd say you are doing a pretty good job!

Cured rock is a broad spectrum. Some people go to extraordinary lengths to ensure there is nothing living in their live rock, others are more than happy to see what hitch hikers they get and keep them alive. I got lucky with mine and still have alive crabs, sea urchins and a goby that came from live rock I had delivered over four years ago.

My idea of cured rock is to let the rock sit in a running tank so that I can see if there is anything beneficial on it I'd like to retrieve, but without the risk of nasties getting into my tank. I would both quarantine it and cycle it cause things will die and you need to do many water changes to ensure the animals present will survive (if that is what you want).


Nevertheless, what you've done is fine. But, because so much had died, you should keep up the 100% water changes as there will be heaps of dead things inside the rock and need to rot. You could probably use fresh water for some weeks to make it easier and later do the same thing with salt water again. Then, put the rock into your display tank to cycle as one normally would.

Do you have a display tank set up already or are you going to set up a display tank starting with this rock?

Now that everything is probably almost dead (judging from your bristle worms dying), I'd consider going the whole way and scrubbing your rock to remove any nuisance algae etc.
 

Ben Daley

/dev/null
Dec 23, 2016
162
101
Melbourne
Thanks for your reply :)

Well, if you wanted to ensure any pests present have died then I'd say you are doing a pretty good job!
I guess that's one way to look at it ;)

I intended to add the LR to an existing display that has been running for about a year to replace the real reef rock that is currently in there in the hopes of adding bio-diversity along with improved filtration. So yes, keeping as much life alive was what I wanted. Because it's going in an existing tank, my plan was to quarantine each piece and observe for pests before adding it to the DT.

I presume all the death is going to leach out of the rock as PO4 for quite some time.
Do you think there's much chance for some of the sponges to grow back from spores? Likewise, do you think the coralline is likely to recover?

Failing that suppose I could try again with smaller batches later in the year (cool temps), run a skimmer and be sure to remove all of the sponges this time :banghead Even if the rock if "fine", I'm reluctant to add it to the DT if there is no microfauna... seems better to take a loss and try again than settle for something else.
 
Last edited:
Sep 24, 2013
367
280
Palm Beach
Thanks for your reply :)

I intended to add the LR to an existing display that has been running for about a year to replace the real reef rock that is currently in there in the hopes of adding bio-diversity along with improved filtration. So yes, keeping as much life alive was what I wanted. Because it's going in an existing tank, my plan was to quarantine each piece and observe for pests before adding it to the DT.
I think replacing all rock is going to cause a lot of unnecessary work, if your goals is to only increase bio diversity.
I've started several tanks with dried rock and all I do, is to add a single piece of live rock, with lots of critters, from someone else. Sometimes I also add a cup of substrate, also from a stablished tank.
One year later and the tank is full of sponges and every other hitchhiker.

I would also not overthink the filtration capacity of LR, provided it alone won't be enough to hold bacteria, in most cases. It would be more effective to add surface media designed for this, to the sump.
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
You'll be fine with the cured rock. Just wait until the sulfur smell is gone. LOTS of water movement is key to getting things back to normal. The other thing you can do during the heat of the day is to freeze some litre bottles of water overnight and float them during the day. You'll be surprised what comes back from the rock. I bring in heaps from Indo and Fiji and it smells like boiled rotten ass when you open the box. It gets cured in the shop, not having that smell in the house.
 

Ben Daley

/dev/null
Dec 23, 2016
162
101
Melbourne
I think replacing all rock is going to cause a lot of unnecessary work, if your goals is to only increase bio diversity.
I've started several tanks with dried rock and all I do, is to add a single piece of live rock, with lots of critters, from someone else. Sometimes I also add a cup of substrate, also from a stablished tank.
One year later and the tank is full of sponges and every other hitchhiker.

I would also not overthink the filtration capacity of LR, provided it alone won't be enough to hold bacteria, in most cases. It would be more effective to add surface media designed for this, to the sump.
I've set up both of my tanks with real reef rock (and a small amount of live rock) and siporax. A year later and I'm not really happy with the results.
It's hard to find examples of successful established tanks using RRR. I appreciate that this is influenced by popularity/market share etc... but it makes me question if there is something missing.
It may be a fruitless experiment but I want to find out for myself.
 

Ben Daley

/dev/null
Dec 23, 2016
162
101
Melbourne
You'll be fine with the cured rock. Just wait until the sulfur smell is gone. LOTS of water movement is key to getting things back to normal. The other thing you can do during the heat of the day is to freeze some litre bottles of water overnight and float them during the day. You'll be surprised what comes back from the rock. I bring in heaps from Indo and Fiji and it smells like boiled rotten ass when you open the box. It gets cured in the shop, not having that smell in the house.
That's reassuring to hear... I hope to be surprised :) We have some more crazy hot weather coming this weekend so I'll try out the water bottle trick.
It was supposed to arrive the same day my partner flew out, but instead arrived 4 days early. She sure was pissed off, hope she comes back :rofl
 
Sep 24, 2013
367
280
Palm Beach
I've set up both of my tanks with real reef rock (and a small amount of live rock) and siporax. A year later and I'm not really happy with the results.
It's hard to find examples of successful established tanks using RRR. I appreciate that this is influenced by popularity/market share etc... but it makes me question if there is something missing.
It may be a fruitless experiment but I want to find out for myself.
Fair enough. However, there are also heaps of examples of tanks with plenty of high quality LR, that also struggle to keep Nitrates under control. On the other hand, there are examples of bare bottom tanks, with minimalistic aquas capes (aka very few LR) and very low nutrients. In other words, high quantities of porous LR is not necessarily the key to success.

The main point being, that LR is not guaranteed to work and there are less troublesome solutions available, such as Organic Carbon Dosing.
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
That's reassuring to hear... I hope to be surprised :) We have some more crazy hot weather coming this weekend so I'll try out the water bottle trick.
It was supposed to arrive the same day my partner flew out, but instead arrived 4 days early. She sure was pissed off, hope she comes back :rofl
If she does come back, she's definitely a keeper!!
 

ReeferRob

Solidarité
Oct 22, 2014
2,661
931
Bel Air
Fair enough. However, there are also heaps of examples of tanks with plenty of high quality LR, that also struggle to keep Nitrates under control. On the other hand, there are examples of bare bottom tanks, with minimalistic aquas capes (aka very few LR) and very low nutrients. In other words, high quantities of porous LR is not necessarily the key to success.

The main point being, that LR is not guaranteed to work and there are less troublesome solutions available, such as Organic Carbon Dosing.
I've often wondered how much of the failed attempts or algae issues come down to the quality of the water used to either top off or make new saltwater? Here in the states using NSW is like some sorta taboo. I'll tell you this, as soon as we move NSW is all I'll be using. I have a bare bottom tank that I don't do a damn thing to other than harvest the macro algae to feed to the fish and top it off. It's 100l and it gets a 5l/week water change. It trucks along and it's using very dense Indo branch rock.
 

Ben Daley

/dev/null
Dec 23, 2016
162
101
Melbourne
Fair enough. However, there are also heaps of examples of tanks with plenty of high quality LR, that also struggle to keep Nitrates under control. On the other hand, there are examples of bare bottom tanks, with minimalistic aquas capes (aka very few LR) and very low nutrients. In other words, high quantities of porous LR is not necessarily the key to success.

The main point being, that LR is not guaranteed to work and there are less troublesome solutions available, such as Organic Carbon Dosing.
I agree with everything you've said and yet I'm still going to swap out the RRR... voice of reason noted.

For a bit more context, my high nitrate issue is not too bad... the highest NO3 I tested was 10ppm, but over the last 6 weeks it's come down to ~5ppm after switching out NP biopellets for nopox. I guess this is more about tweaks rather than addressing a big nutrient problem. I'm sure that BB would work at least as well, but I dislike the aesthetic. Likewise feeding the fish less or having fewer of them would no doubt help too.

Anyway, I still feel the need to switch, I think a part of that is coming from aesthetics and part is general mistrust in man made rock. I don't know if there's something bad in it (like the dye?), or if there's something lacking (animals/minerals/vegetables) or perhaps once of those mysteries of a complex ecosystem that people simply haven't figured out yet. Provided the worst case scenario is wasted effort and money, I'm ok with that.
 

Savage Henry

Member
Feb 2, 2015
653
254
There's a lot of info out there about old live rock becoming a phosphate trap. I don't know for sure if it applies to Nitrates.

My phosphates have been high for years, at approx 0.6, but my nitrates are between 2 to 5.

I think you should consider what corals you want to keep and then set water parameter targets. I have mainly morphs, tics, zoas, palys, hydnophora, and branching hammers. All these are doing well. I would like to reduce my phosphate to 0.1, but I am happy to keep my nitrates as they are.

There are also little factors that you will read about in regards to nitrates that do make a difference. For instance, insuring your liverock (and any other object) you have in the tank doesn't create void areas of low circulation that allow detritus to build up.

I would also suggest that by having a healthy population of bristleworms and other critters in your tank is important in allowing these critters to burrow into your live rock and to clean the live rock out. My thoughts are they act as janitors. For example, I have in the past seen at night small little pebble like solid particles dropping out of holes in my live rock and I think this is from worms burrowing into the rock and excreting detritus etc.

Perhaps such critters can't clean out artificial rock as effective as natural live rock???

Since I currently have a wrasse that is very effective at catching small worms and other critters, I think it eats the critters that would otherwise clean my liverock.

Anyway, a few more things to think about in this underwater world of complexity.