Dry rock curing, in RO/DI only?

[HM3105]

Hey all,

 

Will I be able to cure my Pukani dry rock in RO/DI only, i.e. without adding salt?

 

By "cure" I mean will it start leaching phosphates just the same as it would in salt water or is there some chemical process that requires salt water?

[Clown79]

What are you trying to do? Curing tock is usually done to cycle it and then add it to the tank.

 

If its a new tank, just add the rock and cycle the tank. If its dry rock you will need to introduce ammonia to start the cycle.

 

If you are bathing the rock to reduce phos, there is a method to doing the bath. You can locate the various methods online.

 

This doesn't mean that the rock will never release phos into the tank though

[HM3105]

What are you trying to do? Curing tock is usually done to cycle it and then add it to the tank.

 

If its a new tank, just add the rock and cycle the tank. If its dry rock you will need to introduce ammonia to start the cycle.

 

If you are bathing the rock to reduce phos, there is a method to doing the bath. You can locate the various methods online.

 

This doesn't mean that the rock will never release phos into the tank though

 

My apologies for not being clear. I'm setting up a new tank and I purchased a good amount of Pukani rock from BRS. Said rock is known to have a good amount of organics and most people either dip it in acid or stick it in some saltwater and let it cycle. I am not interested in trying to cycle it in the traditional sense. Its currently on my porch in the middle of January so a bit chilly.

 

What I am interested in doing is getting as much of the phosphate/organic matter into the water column so that it can be removed with lanthanum chloride. I have already power washed the rock pretty thoroughly so at this point it should just be what ever is left.

 

So my question is, do I need to have salt water in order for that process to begin? I'm roughly a week into this and the phosphates are only .03. I guess I was expecting it to be much higher much faster.

[spectra]

Just put it in saltwater and get it going..............

[HM3105]

Just put it in saltwater and get it going..............

 

Fine...........

[spectra]

 

Fine...........

 

Get the cycle going in the bucket.

 

I did all my rock in my 100 in a bucket for 3 months I think and hell no algae growth a small cycle in the tank as expected.......rock looks great now and already has coralline growing on it..........

[blkhwkz]

I've known people to do it in RO/DI alone. I gave mine a muriatic acid bath. Then I put them in a brute can in the garage with a heater and salt water, dosed lanthanum chloride every other day for 10 weeks. Did 2 water changes in that time. I was not trying to cycle them either, just get the phosphates and crap out. Been in the tank for close to 5 months now, no phosphate leeching issues at all.

 

Plenty of people online who have done the same thing but RO/DI water and even though the Hannah checker says saltwater only, apparently works (at least good enough for this purpose) in RO/DI. Just as an example after muriatic acid bath and 2 days in the brute with no lanthanum my phosphates were higher than the ULR checker could read LC kept it in check and I probably could have gone a few weeks longer, but it was down to about .08 consistently when I pulled them out to go in the tank.

[HM3105]

 

Get the cycle going in the bucket.

 

I did all my rock in my 100 in a bucket for 3 months I think and hell no algae growth a small cycle in the tank as expected.......rock looks great now and already has coralline growing on it..........

 

Yeah but then I gotta figure out someway to keep it from getting cold..........

I've known people to do it in RO/DI alone. I gave mine a muriatic acid bath. Then I put them in a brute can in the garage with a heater and salt water, dosed lanthanum chloride every other day for 10 weeks. Did 2 water changes in that time. I was not trying to cycle them either, just get the phosphates and crap out. Been in the tank for close to 5 months now, no phosphate leeching issues at all.

 

Plenty of people online who have done the same thing but RO/DI water and even though the Hannah checker says saltwater only, apparently works (at least good enough for this purpose) in RO/DI. Just as an example after muriatic acid bath and 2 days in the brute with no lanthanum my phosphates were higher than the ULR checker could read LC kept it in check and I probably could have gone a few weeks longer, but it was down to about .08 consistently when I pulled them out to go in the tank.

 

Great!

 

Maybe it's because I dosed with lanthanum chloride earlier in the week...?

[spectra]

 

Yeah but then I gotta figure out someway to keep it from getting cold..........

 

 

A heater duh...............

 

Don't you have a heater for saltwater mixing?

[HM3105]

 

A heater duh...............

 

Don't you have a heater for saltwater mixing?

 

Nope, I've never really needed it. I just heat the water in a kettle since I don't usually let my water sit very long..

[Clown79]

You heat the saltwater in a kettle before adding it?

 

Having a heater for saltwater mixing is essential to match your tanks temp exactly.

[blkhwkz]

 

Yeah but then I gotta figure out someway to keep it from getting cold..........

 

Great!

 

Maybe it's because I dosed with lanthanum chloride earlier in the week...?

 

Could be, easiest way to tell is don't dose the lanthanum for 4 or 5 days and po4 numbers should go up. I wanted to see where my initial readings were which is why I didn't dose right away. When I added the reagent to the water for the Hannah checker and it turned blue while I was shaking it for 2 minutes, I knew the reading was going to be fun. Well worth the extra time though to get this rock cleaned up and stop leeching. Easy enough to chisel caves into and it looks great.

[brandon429]

If your rock was mine id have lightly vinegar cooked the outer layer to speed things up. you had the physical major mass removal down and bacterial action plus currents provided in the water strips the rest off, as much as can be had with the curing process anyway. The whole action of a maturing reef is deposition, which is counterintuitive to the curing process which is trying to export items from the outer layers of the rocks.

 

The vinegar or very light muriatic acid bath cuts those outer layers in five mins what months of bacterial curing and digestion would've removed. Before coralline and animals try and land on the barren spots to colonize it and begin the depositional part...locking the po4 back in/

 

in the end, nutrient rates are so different among tanks that one higher vs one lower isn't really the end of the world, some tanks require more hand guiding than others to remain algae free for a given interval

[HM3105]

If your rock was mine id have lightly vinegar cooked the outer layer to speed things up. you had the physical major mass removal down and bacterial action plus currents provided in the water strips the rest off, as much as can be had with the curing process anyway. The whole action of a maturing reef is deposition, which is counterintuitive to the curing process which is trying to export items from the outer layers of the rocks.

 

The vinegar or very light muriatic acid bath cuts those outer layers in five mins what months of bacterial curing and digestion would've removed. Before coralline and animals try and land on the barren spots to colonize it and begin the depositional part...locking the po4 back in/

 

in the end, nutrient rates are so different among tanks that one higher vs one lower isn't really the end of the world, some tanks require more hand guiding than others to remain algae free for a given interval

 

Question, if I understood this correctly, wouldn't that mean by rock won't leach because the Po4 is locked up in the rock? I mean if the critters are going to colonize it and lock the Po4 back up, then it seems like using acid to remove the outer layers is what releases it in the first place. Therefore, if I didn't use acid, the Po4 was not freed from the rock in the first place, I'm just dealing with any residual surface organics?

[brandon429]

I think the consensus going is that when you submerge those rocks uncured (cured in this case meaning no po4 leaching vs setting in bacteria for the cycle, im following you there) the bacteria begin slowly liberating it from the rock matrix if its there, via digestion as they feed on surfaces, then algae typically gains a foothold and blocks coralline from taking hold. if the organic reserve on the rocks had additional dried worms and plants, things you removed, then the tiny holdfasts they used were still in the rocks and the acid would've cut that layer off vs waiting for natural bio degrading

 

im not sure how required any of this is, just considering the threads from RHF and the problem algae marco rocks threads, I do think po4 plays a role in those types of rocks and there were various ways of mitigating it, the slowest being the unassisted curing process.

 

personally id mortar and pestle some samples into a powder and test that after leaving in a cup of sample water a few days to see if its higher in po4 it would be neat to see results

 

if you were able to lock any po4 in that rock outer layer in coralline and make it bio unavail then maybe the stripping wouldn't be needed. but if the theory is right that only the outermost layers hold the po4 in the caco3 matrix then stripping addresses that in a timely manner. the time it would take for the rocks to coat in coralline would be a long time of po4 leaking from the surface, for algae that already want to take over since there's no coralline to exclude them.

 

in the big problem algae threads we saw lots of entrants posting problems with uncured marco rocks, but cycled ones. though I only deal in purple live rock, we must've seen 1000 marco rocks tanks that skipped curing (for po4, not nitrification curing) and planted corals too early. corals thrived but algae did too really badly, per their posts it seems.

 

I think those rocks ideally should be dark vat cooked with heating and circulation (which fosters the supposed bac they'll see in the tank that liberates the po4) for a long time if not acid etched. the cooking gives the organics missed in scraping time to degrade, and turn loose, and it gives the bac time to seed in the rock and start digesting the layers free of po4, its variable on how long it runs to get to an ideal state. we'd sure need accurate test kits to know.

 

the acid bath speeds that up to five mins... but only if we buy the theory that caco3 holds in po4 that was outputted in close proximity. Ive never tested that to know, but its surely the going theory lol. the scrapable items for sure had waste within them and you got the bulk of that already.

[Clown79]

I did a vinegar bath on mine. Worked very well

[seabass]

Having a heater for saltwater mixing is essential to match your tanks temp exactly.

True, but I don't tend to bother unless I'm changing more than 20%. I'm not saying it's a bad practice, just that I don't usually bother.

 

if you were able to lock any po4 in that rock outer layer in coralline and make it bio unavail then maybe the stripping wouldn't be needed. but if the theory is right that only the outermost layers hold the po4 in the caco3 matrix then stripping addresses that in a timely manner. the time it would take for the rocks to coat in coralline would be a long time of po4 leaking from the surface, for algae that already want to take over since there's no coralline to exclude them...

 

the acid bath speeds that up to five mins... but only if we buy the theory that caco3 holds in po4 that was outputted in close proximity. Ive never tested that to know, but its surely the going theory lol. the scrapable items for sure had waste within them and you got the bulk of that already.

I feel this is basically true for most rocks. However, I believe there are two types of rocks that leach phosphate. The majority of these rocks have been formed in a low phosphate environment (so the rock structure itself is not high in phosphate) and only the outer layer (which often contains dead organics) is responsible for excessive phosphate release. In these cases, a muriatic acid bath can strip off the organics, the outer layer of rock, and most of the phosphate. Even the typical curing process can break down these organics, releasing the phosphate so it can be exported via water changes and/or LaCl3. I think that BRS Pukani rock falls into this category.

 

However, I believe there is another kind of rock, which has been formed in a high phosphate environment. Phosphate is not just on the surface of this rock, but is part of its structure. With this rock, stripping the outer layer with acid removes the surface phosphate, but the rock can still leach phosphate (as it's in the rock itself). Since the total amount of phosphate in this rock becomes lower as it leaches phosphate, I believe it is still possible to cure this rock of excessive phosphate. Although, it might not be practical. I have several hundred pounds of this type of rock sitting along side of my house. However, I'm reluctant to even give it away to a fellow reefer.

[seabass]

HM3105, to answer your original question, I believe that I read somewhere that lanthanum chloride is even more effective in freshwater. So you might decide to treat your dry rock with repeated doses of LaCl3 in RO water (or even tap water), then put it in saltwater, seed it with a nitrifying bacteria culture, and then dose ammonium chloride until the biofilter has become established.

[HM3105]

You heat the saltwater in a kettle before adding it?

 

Having a heater for saltwater mixing is essential to match your tanks temp exactly.

 

No, putting the salt water in a kettle would be silly. I have a small heater and, as seabass said, if I'm doing a water change of sufficient size I'll heat it up to tank temp. However, sometimes the kettle with fresh water is faster and easier. It just depends how big the change is going to be.

 

HM3105, to answer your original question, I believe that I read somewhere that lanthanum chloride is even more effective in freshwater. So you might decide to treat your dry rock with repeated doses of LaCl3 in RO water (or even tap water), then put it in saltwater, seed it with a nitrifying bacteria culture, and then dose ammonium chloride until the biofilter has become established.

 

This is exactly what I am trying to do, pull the Po4 out then it'll go into my new tank where I'll start the cycle. I presumed Lanthanum Chloride should work equally well in fresh water as salt water since its designed by pools but I wasn't sure.

 

My concern/issue was that the Po4, after a 5 days, still hasn't increased above 0.03 per my Salifert kit. My Hanna reagents are MIA at the moment.

 

Seabass and brandon make some interesting points. If the Po4 is locked into the rock structure, then the acid bath would release a lot very quickly whereas letting the bacterial process liberate it should be a slow release correct?

[blkhwkz]

 

This is exactly what I am trying to do, pull the Po4 out then it'll go into my new tank where I'll start the cycle. I presumed Lanthanum Chloride should work equally well in fresh water as salt water since its designed by pools but I wasn't sure.

 

My concern/issue was that the Po4, after a 5 days, still hasn't increased above 0.03 per my Salifert kit. My Hanna reagents are MIA at the moment.

 

Seabass and brandon make some interesting points. If the Po4 is locked into the rock structure, then the acid bath would release a lot very quickly whereas letting the bacterial process liberate it should be a slow release correct?

 

That is my take on it as well. Would also explain why my po4 was so high since I did the muriatic acid bath. If you want to get some weird looks from your neighbors it is a lot of fun. Did it at the end of my driveway on Memorial Day, in the heat, with long sleeve shirt and checmical resistant gloves, a mask with dual respirators and eye protection on. My wife took a few pics and was surprised no one called the cops as I had stuff bubbling out of a container. There were people walking their dogs on the sidewalk that actually crossed the street when they saw me. Looked like something out of an episode of Breaking Bad.

[HM3105]

Well, the holding tank is cloudy and smells nice but no movement in phosphate levels..

[seabass]

I assume the rock is currently in freshwater. I'd probably change out the water. However, it doesn't appear that it's leaching much phosphate (which is good).

 

Also, earlier, I wanted to point out that lanthanum chloride doesn't suck the phosphate out of the rock; it just binds to the inorganic phosphate in the water (forming insoluble lanthanum phosphate). In essence, it saves you from changing out the water to remove the phosphate. So for rock that is constantly leaching phosphate, continued dosing of LaCl3 is required. However, I'm not convinced that we know all of the dangers of dosing LaCl3 in a stocked reef tank, so I have personally reserved the use of lanthanum chloride to prep tanks without livestock.

[HM3105]

I assume the rock is currently in freshwater. I'd probably change out the water. However, it doesn't appear that it's leaching much phosphate (which is good).

 

Also, earlier, I wanted to point out that lanthanum chloride doesn't suck the phosphate out of the rock; it just binds to the inorganic phosphate in the water (forming insoluble lanthanum phosphate). In essence, it saves you from changing out the water to remove the phosphate. So for rock that is constantly leaching phosphate, continued dosing of LaCl3 is required. However, I'm not convinced that we know all of the dangers of dosing LaCl3 in a stocked reef tank, so I have personally reserved the use of lanthanum chloride to prep tanks without livestock.

 

Correct its in fresh water. I'm going to add salt today I think.

 

I was hoping to avoid using LaCI3 in the stocked tank, especially since I'm using a brand I haven't heard anyone else mention or reference.

[HM3105]

I think we're moving in the right direction, Po4 is up to .133 per my Hanna checker..

[seabass]

And that's a good thing?