How long do you cure dry pukani?

JOKER · Apr 11, 2016

Ok so I have some dry pukani from BRS curing in Rubbermaid , and I am wondering how long do you guys and gals cure. I keep checking with hanna and get different readings. One day it reads .09 then .03. I think the rock is ready, but I want to be sure. No smell from rock, and water is clear. I am thinking I want to get some of this rock into the sump for the new tank I am building and get the sump running before the tank is running. All this rock has been through bleach bath for 24 hours, vinegar bath for 24 hours, then dried out for several days before being cured. What are your thoughts? Thanks

fab · Apr 11, 2016

You should not need to cure this dry rock at all. There should be no critter|organic residue left on it to get rid of. Now that doesn't mean your tank will not have to cycle. You still have to let the biological cycling process run its course of growing a tank-wide bacterial culture that will provide natural filtration in your aquarium system.

...A few more words on this for you:

http://www.reefcentral.com/forums/showpost.php?p=24096538&postcount=6

I hope this helps you.

luke33 · Apr 11, 2016

FWIW, premium aquatics cured this for 4-5mths before selling it to customers. I purchased some after it had been curing for 3+mths and it still leached some phos for a few mths. After 6mths its not leaching anything but it still will not grow any corraline algae. My entire back wall and bare bottom are completely encrusted and corraline grows like a weed everywhere except on the rock. So to me its cycled but not mature.

fab · Apr 11, 2016

Leaching and 'cycling' are different processes entirely Leaching is a chemical process. Cycling is a biological process. They don't have anything to do with each other beyond the fact that leaching can contaminate a tank and disrupt its ability to cycle, depending on which chemicals are being leached into the tank water.

BTW, successful cycling results in your tank being able to process a bioload within a timeframe. For example, if you introduce a bioload of 2 ppm Ammonia and your system eliminates it within 24 hours then your tank is considered to be cycled. You can do this by adding 2 ppm of Ammonia. It helps to raise your tank temperature to 82 degrees F to speed up the cycling process. Another way some people like to test for the completion of cycling is to put dead shrimp (from a fish market) in the tank and watch how long it takes for it to completely disappear. I'm not sure how you would quantitatively score this type of test, but it is a simple one to perform.

Aquarium Art · Apr 11, 2016

I like to do somewhat of an acid wash before I let pukani soak(otherwise you will have issues with phosphates)

luke33 · Apr 11, 2016

Yes, thanks for the info, I understand the diff : ) I believe the original poster is wanting to know if his rock is cured. I just wanted to add input because I am using the same rock and have went through this whole process with it. It does take a while to cure any dry rock imo so I just want the poster to be aware it takes a while. It is not like adding in cured LR.

jason2459 · Apr 11, 2016

Pukani Dry rock has become very well known to leach a lot of phosphates over a long period of time. I've started with it on two different tanks way back when it first came out and also had that issue myself before it was well known to do this (well known at least on forums.)

Also, it may be dry rock but there are still dead organics in the crevaces I've found.

I really like the pukani dry rock otherwise for it's looks and porosity. If I could do this again I would do one of two things.

1) Quick Acid bath to strip the top lay off and then soak in saltwater with a pump running and dose lanthanum chloride while monitoring the PO4 levels until it was no longer leaching out.

2) Start with a tampa bay live rock package.

fab · Apr 11, 2016

luke33,
Got it! I have used Pukani, both live and dry. Unfortunately it is like putting a bag of phosphate in my tanks and letting it leak out slowly. I love the look, but the phosphate is a PITA and phosphate removal is not free.

P, I was not being critical of you, just clarifying to the OP.

luke33 · Apr 11, 2016

fab said:
luke33,
Got it! I have used Pukani, both live and dry. Unfortunately it is like putting a bag of phosphate in my tanks and letting it leak out slowly. I love the look, but the phosphate is a PITA and phosphate removal is not free.

P, I was not being critical of you, just clarifying to the OP.

Its all good Fab, and agreed, this rock is nice but it takes a while to turn into good lr. I used LaCl for months until my phos became stable between 0.00-0.06 but its odd as corraline algae still will not grow on it.

If I were to do this again, I would go with Jason's #2. I really think it will take a year or so for the pukani to really mature.

JOKER · Apr 11, 2016

This rock has also been through muriatic acid bath. I have ran GFO in one container with the rock and it seems to still have some phosphate. I am running powerhead and heater in both. I really like the rock and have built my structure with it. I also have some shelf rock that I will cure later, will it also leach phosphate like the pukani? Thanks for the replies. I thought it would be some time the rock has been curing for almost a month now.

luke33 · Apr 11, 2016

Well phosphates aren't necessarily the enemy as I like to keep phos in my tank's all the time, its just when they start climbing higher than I would like to see. Sounds like you have cured your rock pretty well at this point so just set it up and let her rip. If you start seeing your phos creep up just use some gfo or LaCl to bring it back to a safe place. Then when that phos finally stops leaching you won't need to address it. Tough to say on the shelf rock, just test the water with a hanna checker and treat accordingly.

Also if your just getting between .03-.09 I wouldn't be to worried about it to much as that isn't bad. If I were in your shoes I'd start the cycle.

JOKER · Apr 12, 2016

Thanks guys I was thinking I should be fine, but never hurts to ask. I know the hanna checkers are good but I get different readings back to back. I think I will give it a go and get the sump running with what will fit in it, and keep the other cooking until tank finally gets here. I think when I get some nitrate the phosphate should even out naturally. Been waiting a year now for my reef savvy.

luke33 · Apr 12, 2016

Hmm, that's strange on the hanna readings as mine have always been spot on if I go back to back on testing. Are you holding down the button until the 3:00 timer comes on? I'm betting you are, just thought I'd ask : )

JOKER · Apr 12, 2016

Yea it is strange. Sometimes it does well but others it reads differently. I use a micro fiber rag to wipe off vial each time also. If I use other phosphate test I show 0 so I think im good. Can always get it down with GFO or something if it rises any. I am taking this tank slowly so im in no hurry at all.

alyee5 · Apr 12, 2016

IMO you are well on your way and on track.
I cured my Pukani in heated/flowing SW for about 3 months after bleaching and muriatc acid dipping.
I didn't have a Hanna ULR PHOS checker until the last few weeks of curing. It measured near zero after I used PhosFree pool product for a few times.
I never had any uglies during the 3 months of curing- no algae, no foul smelling water (only did a couple of water changes).
The Pukani has been in my tank a total of 6 months and only minor film algae (tho I am taking the cycling and adding of livestock very, very slowly). I haven't even bothered measuring the phosphates. I will do so as now I am curious. I have a BRS dual reactor but haven't set that up either.

JOKER · Apr 13, 2016

That would be good to know if it is still near 0. I have been using phosphate RX from time to time and done 3 water changes on this rock.

alyee5 · Apr 16, 2016

Sorry for the delay. Well I took 2 readings yesterday with the Hannah and it read zero both times. I did another using another batch today and got zero again. Not sure if I believe zero 's so I will try another measurement with another box of reagent I have and try the Salifert kit for kicks. (And research "zeroes on the Hannah ULR")

JOKER · Apr 16, 2016

Its all good. Thanks for the reply. I am thinking once I start the cycle nitrate will shoot up and phosphate will drop. I hope to get that started this next week.

Ocelaris · May 4, 2016

I wanted to add my $.02 to the Pukani leaching phosphates as I'm in the process of cycling (it's been about 2 months, NH4/NO2 is down, NO3 is starting to go up). The big Pukani pieces that I got had tons of dead, dried critters in them, to the point that I'm convinced that it's just taking forever for the material in the crevices inside of the rock to decompose. I'm just saying that it may not be bound calcium phosphates, but organic matter that has to work it's way out; in which case I'm not sure an acid bath is a 100% fool proof solution (I don't know, maybe a weak hydrochloric solution decomposes organic matter?). But if we're talking decomposing organic matter, maybe an oxidizer such as peroxide would be more effective. Just my thoughts.