# Pukani Experiment



## Johnnycat

I wonder if you guys can help me out with an idea for an experiment.

In setting up my new tank(s) I've ordered some BRS dry Pukani rock. This stuff is awesome. It is really light and porous, but has the reputation for leaching phosphates over a long period of time. 

Search "Pukani Dry Rock" and several suggestions will come about. Many have suggested various methods to deal with the phosphates:

1) Soaking in bleach prior to "curing" - the idea is to dissolve/remove some of the caked on dead organics that would slowly break down and release nitrates and phosphates.

2) Acid bath (muriatic acid or vinegar seem the most popular) - the acid dissolves the top layer of the rock, which is basically calcium carbonate. In doing so it releases a lot of the bound phosphates. The downside is it can also eat away a lot of the dry rock. It also requires special handling and ventilation due to the acids and the fumes created.

3) Slow cook time with lanthanum chloride (Seaklear) to bind phosphates. Most people add the Seaklear every few days while cycling the rock in a dark bin of saltwater. The Seaklear precipitates the phosphate and does not appear to affect the curing or cycling process. 

While there is a ton of anecdotal information, along with speculation as to what should and should not be done, no one has done a good head-to-head with the various methods (at least to my knowledge). 

So, what I am proposing is a little biology experiment. Assuming these rocks do leach phosphate (something that would have to be measured with my sample first) I plan to take roughly 20-30 pounds and place into separate bins. 
- One will be a "control" in which I do nothing but cycle the rock with saltwater and follow a regular "curing" protocol. 
- The next will be the bleach bin - soak in bleach about 24 hours and then follow the curing protocol. 
- Next will be the Seaklear bin - bleach and then add Seaklear every few days for several weeks. 
- Next, Muriatic acid bath then regular cure. 
- Finally, the "extreme cooking/curing bin" with bleach, acid bath, then cure and if phosphates are still present Seaklear can be added.

The end point will be time to see a reduction in phosphates. 

I know I will end up with WAY more rock than I need, but I thought it would be interesting.

Any thoughts or comments are appreciated.


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## coralbandit

All sounds interesting and I'll be following.It is said all coral/rock with precipitate phosphate over very long time periods.I don't think any of those methods will effect the "long run".I mean "scratching the surface" will not change what is many layers below,that will only become exposed over time?
Have you considered just running a good reactor with GFO to remove phosphates?I would think that would work as well and is more easily applied.


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## Johnnycat

coralbandit said:


> Have you considered just running a good reactor with GFO to remove phosphates?I would think that would work as well and is more easily applied.


When I finally get the tanks up and running I plan to run GFO - absolutely. It looks like that will be several months due to likely moving to a different house at some point this year, which is one of the reasons I decided to go with dry rock.

The stories about the Pukani rock are pretty amazing though - almost everyone loves it but there are some that have fought algae outbreaks just on the Pukani rocks. Others have fought phosphate problems until they took the Pukani out of their tanks and used one of these methods. Of course - it's the internet, so we must take it with a grain of salt.

There are soooooo many variables in this hobby that I agree it's hard to pin problems like algae outbreaks just on one variable (the rock). But hey - I need something to keep me busy until the move! I figured I could play with this and take up Pod farming (stay tuned for that thread!)


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## Johnnycat

Update on the Pukani experiment - it would be a ugh mess to run a good experiment the way I want, not to mention space and time consuming. 

I got my Pukani rock along with some dry Fiji and Tonga branch. All are great rock. 

Today I spent put all the rock in a Rubbermaid 150 gallon water trough and added bleach (10:1 ratio water to common bleach).

Tomorrow I plan to do an acid bath with muriatic acid. 

Then start the cycle, wait, measure parameters, wait some more, add SeaKlear if phosphates are high, and generally give it time.


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## Johnnycat

LOL - Well, I am such a wimp. 

There I was, with 100 pounds of gorgeous Pukani dry rock (along with about 75 pounds of decent regular Fiji dry rock) fresh from the bleach bath in my 150 gallon feed trough. I had 12 gallons of muriatic acid ready to go (for a 10:1 ratio as recommended), and then I started looking at the Pukani.

I've read on forums where others have done the acid bath with good results but everyone agreed that the acid eats away at least some of the Pukani, as porous as it is. Some have had disastrous loss of good pieces of Pukani. 

So as I stood there admiring the Pukani, it occurred to me - I'm not in any hurry and I can get phosphate free with Landanum chloride over time. I put the acid away for now. 

In the recent cold weather my RO/DI unit crapped out so I need to get the parts to patch it up. Right now I'm forced to have tap water in the trough with the rocks. Hopefully I can get the RO/DI unit fixed soon and make fresh salt water. 

So, given the choice of 
a) no water 
b) fresh tap water without salt
c) tap water at ocean salinity

what would you choose?


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## Johnnycat

RO/DI unit is finally functional, so tap water is drained and tank is filled with RO/DI water. The plan is to drain this RO/DI as a final rinse to make sure chlorine and other tap water stuff is out and then fill with saltwater. That is, if can get this done before the water lines freeze.


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## coralbandit

Good luck!
Are you going to start cycling when you get the rock in salt water or keep soaking/rinsing it.
There really are lots of PO4 removers that I wouldn't risk good rock .You're not a wimp,if the rock looks good then run with it,You'll never get maintenance free with reef!


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## Johnnycat

Okay - the saltwater is in. I went ahead and put some Dr. Tim's ammonia in there too. I have heard others saying the Pukani has so much dead junk in the pores and crevices that adding a raw shrimp or plain ammonia is not necessary to start a cycle, but I added some just to make sure we get this thing started. 

I had some odd Biospira and DFS nitrifying bacteria lying around so I added that - not sure if that really makes a difference but the microbiology seems to make sense. Those bottles aren't old, but they're not fresh so I don't even know if the cultures are still alive. If not, no biggie. I estimate that I have at least 3 months before I'll need this rock.

Let the cycle begin!


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