Dry pukani rock and phosphate leaching, best practices?

[twowilldo]

Could use some advice here… I bought a small piece of dry pukani (.8 lbs.) yesterday with the intention of adding it into my Spec V zoa/paly only tank (after curing and cycling it first). The tank already has pukani and Fiji rock in it and phos results are less than .1 (about the color of dark urine using the Seachem kit). I have a mini bag of Purigen in the media box.

 

I put the scrubbed rock in a small (darkened) bucket with circulating salt water and tiny heater; with a bit of Seachem Stability in there and a few bits of shrimp to get things going.

 

I’ve read that this type of rock has a tendency to leach phosphates and sure enough, when I tested the water this afternoon, I got a reading of 1.0. Should I buy some lanthium chloride to hasten the process or is a rock this small going to leach out quickly on its own with water changes (after cycling)?

 

Or, am I completely going about this in the wrong way?

 

Appreciate your thoughts, thank you!

[Thrassian Atoll]

Are you sure the dead shrimp isn't causing the phosphates?

[twowilldo]

I guess it could be Tilton... been reading and surfing about the pukani and phosphates. When I started this tank not quite 4 months ago, I didn't have this issue with the rock. 

 

I wonder if I am going about this the wrong way... maybe I should just soak this little rock in heated and circulated RODI and forego any attempt at getting some sort of life going on it until I can tell if phosphates have stopped leaching into the water? Technically I wouldn't have to even use salt water since there is no life on it, right?

 

Thanks for the reply too BTW.

[NanoReefMinimalist]

I bleached it for 48 hours and cured it for a week after the bleach. The phos is not detectable. 

[twowilldo]

Seems simple enough. What was your water to bleach ratio? 

 

Thanks for the feedback too...

[NanoReefMinimalist]

7 minutes ago, twowilldo said:

Seems simple enough. What was your water to bleach ratio? 

 

Thanks for the feedback too...

I don't remember.  Try to search BRS's youtube video about bleaching dry rocks.  I think more does not hurt.

[twowilldo]

Right, didn't look at the video but read a few comments and seemed like 50/50 was doable... bleach is certainly cheap enough. I like this approach better than using the acid and afraid that using the muriatic acid will take too much of the rock surface down and increase the leaching problem in the long run.

 

This rock looks pretty cleared off of material on the outside, but all those tunnels and things, who the heck knows what dried up and died in there?

 

 

[NanoReefMinimalist]

7 minutes ago, twowilldo said:

Right, didn't look at the video but read a few comments and seemed like 50/50 was doable... bleach is certainly cheap enough. I like this approach better than using the acid and afraid that using the muriatic acid will take too much of the rock surface down and increase the leaching problem in the long run.

 

This rock looks pretty cleared off of material on the outside, but all those tunnels and things, who the heck knows what dried up and died in there?

 

 

I really like this rock. 

[twowilldo]

Yeah I like it too, much more interesting and the holes make nice little anchors for the frags.

 

I'll pull that rock out tomorrow and start bleaching it, then curing... then testing for phos without the extraneous stuff as Tilton pointed out.

 

It's just a little rock but the Spec V is small and the addition will add about 25%+ more volume overall, so I want to be careful not to upset the system at this point.

 

Thx again.

 

[graftobny142]

I had some rock testing at .5ppm phosphate, and am using Lanthanum Chloride to bring that down to near 0

[twowilldo]

I think I've been following a thread of yours (or someone, I've looked at several at this point) about that... what I wonder is if the LC or SeaKlear or whatever people use, is a temporary fix?

 

It seems many people do the acid dip but maybe that exposes too much of the original hard surface of the rock? What are your thoughts about that? Did you dip in acid also? I like the bleach idea for clearing out the tunnels and holes.

 

It concerns me enough that I don't want to open up a can of worms by adding this rock and causing a phos problem in such a small environment (5 gals). But then again the rockwork needs more stability, I thought pinning/dowling the rocks when I built it would be enough but it really just isn't enough.

[graftobny142]

If you do it right, the LC/Seaklear won't be temporary.

Basically you dose it a few times over say a week, test phosphate, repeat. Giving the water time between dosing to absorb more phosphate from the rock. The water takes in phosphate until it is balanced with the phosphate in the rock. So if you keep the dosing/rest cycle going, eventually it should take most of the phosphate out.

I'm not going to acid dip but I am going to use bleach, seems simple and effective.

[twowilldo]

Okay. The rock is small enough that it can soak easily in a gallon or two of water and changes should be pretty easy.

 

I'll just follow what the rest of you are doing and see how it goes.

 

I think this will have to be an excuse to by that Hanna checker... heh.

[graftobny142]

25 minutes ago, twowilldo said:

Okay. The rock is small enough that it can soak easily in a gallon or two of water and changes should be pretty easy.

 

I'll just follow what the rest of you are doing and see how it goes.

 

I think this will have to be an excuse to by that Hanna checker... heh.

Its what made me pull the trigger on a Hanna Checker too.

Make sure to get the phosphorous one, can read to a more accurate value with a very simple conversion chart.

https://www.bulkreefsupply.com/phosphorus-ultra-low-range-colorimeter-hi736-hanna-checker-hc-marine-water.html

[Nart]

@NanoReefMinimalist Curious. What PO4 test kit did you use when you were curing your Pukani and how much Pukani were you curing?

 

I took almost the same approach as you with bleach. But I bleached for 24 hours, then 24 hours vinegar bath... it's been about 53 days now and it's barely done curing.. PO4 is around 0.02 I think. Can't really tell with these color charts from Red Sea.

[Five.five-six]

Lanthanum Chloride is serious business, your math needs to be dead on.  I would just use GFO or one of the other phosphate absorbers on a smaller tank, especially with only 1.0 PPM phosphate, which isn’t wildly out of control. 

[graftobny142]

10 hours ago, Five.five-six said:

Lanthanum Chloride is serious business, your math needs to be dead on.  I would just use GFO or one of the other phosphate absorbers on a smaller tank, especially with only 1.0 PPM phosphate, which isn’t wildly out of control. 

 

 Be carefuo only f you are dosing your tank. Curing rock you can go hog wild with it.

 

How woild it be bad in your tank. The precipitate will fall out on stuff and make a mess if you didn't use a filter sock, but not poison it.

[twowilldo]

I don't plan to use that stuff right in the tank... this is only to try to prepare this rock in advance... in a plastic tub. The pukani is currently soaking in a bleach solution. Hanna checker has been ordered. I will use my el-cheapo Seachem kit until the checker arrives, at least I will have something of a baseline for now.

 

I read some threads about dosing directly into tanks (and sumps) and using socks to catch the precipitate. Don't want to do that if I can help it. Such a little tank, can get it out of whack way to easily.

 

Thanks again all for your thoughts.

[Five.five-six]

16 minutes ago, themummra said:

 

 Be carefuo only f you are dosing your tank. Curing rock you can go hog wild with it.

 

How woild it be bad in your tank. The precipitate will fall out on stuff and make a mess if you didn't use a filter sock, but not poison it.

That and if your phosphate is actually 0 your coral will starve.  

[MainelyReefer]

Pukani has been a 2 year headache when uncooked in my 40, though it has all leached out finally and I killed the algae off mostly.  Definitely bleach it, get it so there is no more bleach in the rock then acid wash it, a small bath of vinegar may be sufficient but with large quantities muriatic acid is preferred.  I would think after these treatments the lanthanum chloride treatments wouldn't even be necessary unless it was larger chunks like I had with hard to reach places with dead things throughout. I am in process of cooking the remaining 30 pounds I have

[spectra]

Not sure if you bleached the rock yet but I have heard of issues with Pukani and when setting up my 100 I used 40lbs or so. I soaked in a 20% vinegar water solution for a weekend then scrubbed the rock and rinsed it. Rock then soaked in a brute with salt water, heater, power head and a skimmer for 3 months. I did water changes with tank water and also added bacteria to the mix. Worked out well and have not had any issues and tank has been up for over a year now.

[twowilldo]

Update (for what it's worth):

 

After a 48 hour 4:1 bleach soak, I power washed and submerged that small rock (less than a pound) into a 5 gal tub containing distilled water, dosed with one tablespoon of SeaKlear. As predicted, the water clouded up. I've been changing the water a few times per week, each time scrubbing the surface of the rock with a brush to get off any precipitate that may have settled on it in addition to scrubbing the bucket; and repeating the dosing/soaking. It looked like the cloudiness had finally abated, so placed it in undosed, non-LC water a few days ago and still, after three weeks I am still getting high readings (53 ppb or .162ppm), using the Hanna ULR checker. I'd be happy if I could just get it to .03 at this point. I've been double-checking with an almost used up Seachem kit and it backs up the findings from the Hanna (at a basic level anyway).

 

I have to wonder if I hadn't have started this process outside of the 5 gal pico DT ahead of time, how bad it might have caused crazy algae growth as well as affecting the health of the soft corals in there.

 

Patience is a virtue, I suppose.

 

[Jaredgib]

I just pulled 26 pounds of pukani out of a bleach bath, 10:1 ratio after 5 days. I rinsed it off and put it in RO water with Seachem Prime to dechlorinate. I plan to rinse it daily over the next few days and replace the water. Once I have no detectable chlorine, I’m going to start curing for my tank swap.