Back after 30 yr break!

[yachty]

Wow, have things moved on!

I feel like a beginner again..... Anyway, I've got some second hand dry live rock and wasn't able to get much background on it so I decided to do a bleach / acid wash. I've rinsed it in RO water now.

My question is should I still cure it in a barrel of salt water? I have time as the tank is not set up yet?

Cheers steve

[colg]

Hi Yachty

Good plan on cleaning the old rock. Not sure whether soaking it in saltwater would be of any benefit. If you used NSW and created some water movement you might get some colonization of good bacteria. You will still go through a cycle when you start up the tank so, IMO it probably isn't worth it. By all means keep soaking and replacing water as this will help remove any phosphate that is still leaching from the rock.
Cheers,
Col

[yachty]

Hi Col,

Thanks for the information. I was thinking of doing what you suggest, so I feel reinforced now.

I was surprised at the phosphate in the rock after the acid/ bleach. After 3 days in Ro water it is .25 ppm. I'm not sure how that stacks up on a scale but I will keep doing weekly changes on the rock till the level starts dropping.

Is there a recommended level?

Cheers Steve

[colg]

Zero is a good level.
If you have phosphate leaching from your rock you could/will be fighting a battle with algae until it all comes out.
I have heard of people vinegar bathing rock to etch off a layer (same as acid I would guess). I don't know if this really works, as I would think the po4 would go in quite a depth.
How long did you soak in bleach for? Some people cook their rock for a couple of weeks.

[yachty]

I bleached for 24 hrs. I figured that is plenty of time for it to do its job.
The acid was about 20 minutes as ididnt want to loose too much rock in the process. I use the salifert PO4 kit, so not sure if it's .1 ppm or . 25ppm. I'll keep soaking and testing till I get it it to zero.

[yachty]

Just curious about how the phosphate got into the rock. Is it from the previous users high levels in his tank or is it just part of the rock itself?

[shrimpman]

It might be an idea to use a large amount of GFO to pull the phosphate out. Usually, you would not use a large amount in your tank because it has the ability to strip the water of trace elements, however, in this case its perfect. You not going to be using the water and you want everything stripped out