Another Pukani thread...please help

[Mr. Microscope]

Hello All,

 

Hoping for some experienced Pukani users to chime in here. Here's the breakdown:

 

15ish lbs. Pukani.

2x muriatic acid treatments (smaller reaction second time) + scrubbing the rock after and picking at crevices with tweezers (removing organic material, sponges, etc.)

 

Now sitting in bucket with powerhead and RODI water.

 

Test RODI with Red Sea kit for PO4

Freshly made RODI 0ppm

After 24 hours about 0.25ppm

Change to freshly made RODI

Repeat

 

It's been in RODI for about 4 days now. After 24 hours each time I get about 0.25ppm.

 

 

Questions:

How much longer can I expect to see high PO4 readings?

 

Do you think I'm getting accurate test results from RODI since the system was designed to work with salt water?

 

Any way to speed up the process?

 

NOTES:

1) I don't want to invest in LC.

2) No more acid, the rock is already too melted away.

3) I'm out of GFO.

 

Thanks!

[jservedio]

I would definitely check in with someone who has a Hanna ULR checker before going too crazy with anything to make sure your phosphate test kit is working properly.

 

There is really no reason to use Lanthanum or GFO when you can just change the water out of the bucket since they are effectively doing exactly the same thing. You are just removing phosphate from the surrounding water so there is an ion gradient - no reason to use a chemical media to when you can just do a 100% water change. Put the rock in the biggest bucket you can and change the RODI every day while you are sourcing a Hanna ULR. If the Red Sea kit doesn't change to below 0.25ppm in a few days, it is definitely bad.

[Mr. Microscope]

Thank you!

If the Red Sea kit doesn't change to below 0.25ppm in a few days, it is definitely bad.

Do you mean the kit is bad, or it's a bad sign for the rock?

[yman182]

Eric,

 

I would double check your results. I just had a red sea kit go bad on me (lot 103). It kept saying i had po4, but my other kits did not. I emailed them and they sent out a new kit. Just some food for though.

 

I have a Hanna Phosphate ULR reader if you would like to borrow it.

 

-Yury

[seabass]

I got a batch of rock rock from Marco Rocks that leached even more phosphate. It took months of treatments before phosphate stopped leaching levels less than 0.03ppm. Treatments can be lanthanum chloride, GFO, or water changes. Acid baths do nothing to prevent rocks from leaching, they simply clean the surface (actually strip off the outer layer) of the rock. Lanthanum chloride is easier than water changes and is cheaper than running GFO; however, I would only use it to prep rock (and not in a stocked aquarium).

[jservedio]

Thank you!Do you mean the kit is bad, or it's a bad sign for the rock?

I was talking about your test kit.

[afyounie]

So is pukani known for leaching phosphates? I never scrubbed or cleaned the giant piece I have because I was dumb. This might explain why there is so much more green micro algae growing on it and why thin coats of cyano grow on it every once in awhile. Also why bryopsis grew all over it but not on the BRS dry rock. And why I have to run so much GFO to strip phosphates out. How long does this typically last? Sorry for hijacking your thread.

[Mr. Microscope]

Eric,

 

I would double check your results. I just had a red sea kit go bad on me (lot 103). It kept saying i had po4, but my other kits did not. I emailed them and they sent out a new kit. Just some food for though.

 

I have a Hanna Phosphate ULR reader if you would like to borrow it.

 

-Yury

Awesome! Thank you for the info on that lot. I checked my box and it doesn't have a lot number on it! Just and expiration date. Grr. Perhaps it's because it's a combo kit (Nitrate and Phosphate). I'd love to borrow your Hanna! Thank you for the offer. I'll PM you about it.

I got a batch of rock rock from Marco Rocks that leached even more phosphate. It took months of treatments before phosphate stopped leaching levels less than 0.03ppm. Treatments can be lanthanum chloride, GFO, or water changes. Acid baths do nothing to prevent rocks from leaching, they simply clean the surface (actually strip off the outer layer) of the rock. Lanthanum chloride is easier than water changes and is cheaper than running GFO; however, I would only use it to prep rock (and not in a stocked aquarium).

Thank you for your input seabass. I'm definitely planning to do all the prep for this rock out of the tank.

I was talking about your test kit.

Well, I am seeing changes in results as time passes. It starts off at zero with fresh RODI, then goes to 0.25ppm after 24 hours. I let my last batch sit another 24 hours and got results closer to 0.36ppm. So, I think something is happening. I don't mean to be contradictory as I'm definitely open to the possibility that my test kit is crap, but do you think the gradual change in results might indicate the contrary? Should I push it to three or four days before water change and see if the results go higher than 0.36ppm?

So is pukani known for leaching phosphates? I never scrubbed or cleaned the giant piece I have because I was dumb. This might explain why there is so much more green micro algae growing on it and why thin coats of cyano grow on it every once in awhile. Also why bryopsis grew all over it but not on the BRS dry rock. And why I have to run so much GFO to strip phosphates out. How long does this typically last? Sorry for hijacking your thread.

Yeah, do some searches for Pukani and you'll read all sorts of horror stories about algae outbreaks. It's the coolest looking and lightest (highest surface area for nitrifying bacteria filtration) stuff on the market IMO, but it takes a lot of prep work to get it usable.

[afyounie]

Well crap. I researched everything but the dang rock. I even checked to make sure the BRS dry rock wouldn't leach. But I didn't check about the pukani. I really like the stuff, but I wish I had done more research. Well, at least I know now. Next time I will definitely cure the stuff in a separate container before using in the tank.

[seabass]

How long does this typically last?

Months of treatments. I've treated rocks daily for more than 6 months and they still leach some phosphate (but now they don't leach enough phosphate not to use them). Each treatment (LC, water change, or GFO) reduces the total amount of phosphate left in the rock.

 

As Mr. Microscope is seeing, the rock leaches out in an attempt to reach an equilibrium. At some level the phosphate will stop leaching out. So even if you just left the rock in the a tub of clean saltwater (or RO/DI) for more than a year, the rock would soon stop leaching until you either change it or treat the water again. It could require lots of successive treatments to get the level down to 0.03ppm or below.

[yman182]

I had the phosphate and nitrate kit. Both were off. I got a salifert kit and the hanna they show the same results. Red Sea is sending me a new kit, but it is still a pain to think you have a problem in your tank when you really don't.