Testing PO4 after nuking LR rock question

[cvrle1]

I got a bunch of LR rock from local reefer that was sitting in buckets (without water) for several months. After I got them home, i did a bleach bath for a week to kill and get rid of all dead organics. Rocks came out white and clean, so that was good. Rocks dried out and sat dry in a plastic tub last several months and there is no sent of bleach.

I filled up plastic tub full of rocks with RODI water 2 days ago and placed couple of powerheads for water movement. Checked PO4 using Hanna HI736 (ULR Phosphorus) and got reading of 1, which converted to PO4 comes out to 0.003 PPM.

Have few questions about this:
Since I am not curing or cycling rock yet, but just checking to make sure PO4 doesnt leach, is using fresh RODI water without salt fine for this test?
I was going to keep checking for next 7-10 days to see if numbers change. Is this enough time, or should I test for longer periods?
Anything else I may have missed that i should be doing?

Thanks for the help

[Scrubber_steve]

Originally Posted by cvrle1

Have few questions about this:
Since I am not curing or cycling rock yet, but just checking to make sure PO4 doesnt leach, is using fresh RODI water without salt fine for this test?

I believe you need a freshwater Po4 test kit for this.

Originally Posted by cvrle1

I was going to keep checking for next 7-10 days to see if numbers change. Is this enough time, or should I test for longer periods?

If there is no,,, or low Po4 reading after a week I would just put the rock into salt water. If the Po4 reading is high after a week, say 3ppm, do a fresh water change. If your tap water is town supply that will do,,, don't waste the RODI. Just get the Po4 low & then switch to saltwater bath.

Originally Posted by cvrle1

Anything else I may have missed that i should be doing?

When you're happy with the Po4 reading, cycle the rock in the tub.
Add microbacter, or some other starter culture, add a prawn & measure you NH3/4, No2, and then No3 & Po4.

Keep the cycle in the dark.

[cvrle1]

Originally Posted by Scrubber_steve

...

When you're happy with the Po4 reading, cycle the rock in the tub.
Add microbacter, or some other starter culture, add a prawn & measure you NH3/4, No2, and then No3 & Po4.

Keep the cycle in the dark.

Thanks for the info. After thinking about this more, I decided to do what you mentioned above. I will add salt and bacteria and start the cycle. It will take few months to finish, so it will be ready by the time tank is setup as well. Need to get some heaters, as rock is in garage, so it's cold in there.

Thanks for the feedback.