Curing rock method

[HippieSquirrel]

I want to cure my rock before using it this time around, really I’m looking to leach as much of the phosphates etc over the course of 1-3 months while I get my build set up.  The plan is to buy dry rock (nothing live not dealing with hitchhikers) and leave it in freshwater (not sure about RO or tap yet)  in an opaque bin with a power head/air stone.  When ready I’d do a wash with maybe vinegar or acid and then sit it in RO for a day or two.  

 

Will this work?  Is there value in doing this?  Haven’t done it before and it seems people have a lot of different ways of curing/prepping rock (or lack of prep) as well as different reasons for doing so like cycling out of tank which isn’t what I’m worried about.  

 

If if I were to do the same with some rock from an existing tank that has lots of algae could I salvage the rock without transferring the nuisance/macro algae?  It has grape caulerpa which is the main thing I want to get rid of.  

[DaveMc]

Following along, need some idea's for this myself lol.

[seabass]

4 hours ago, HippieSquirrel said:

I want to cure my rock before using it this time around, really I’m looking to leach as much of the phosphates etc over the course of 1-3 months while I get my build set up.  The plan is to buy dry rock (nothing live not dealing with hitchhikers) and leave it in freshwater (not sure about RO or tap yet)  in an opaque bin with a power head/air stone.  When ready I’d do a wash with maybe vinegar or acid and then sit it in RO for a day or two.  

If the tap is high in phosphate, then you should use RO instead.  I would change the water out frequently (exporting any leached phosphate).  There isn't really a need to aerate the water.

 

A vinegar bath won't do that much.  The calcium will buffer the acid fairly quickly and it'll lose strength.  A stronger acid bath will remove some bound phosphate on the surface, as well as dead organic matter.  However, sometimes the phosphate is just coming from the decaying organics.

 

Once you're done with the freshwater cure, you should build up the bio-filter: http://www.drtimsaquatics.com/resources/fishless-cycling

 

5 hours ago, HippieSquirrel said:

If if I were to do the same with some rock from an existing tank that has lots of algae could I salvage the rock without transferring the nuisance/macro algae?  It has grape caulerpa which is the main thing I want to get rid of.  

If you give up on the other life on the rock, there are a few ways that you could get rid of the algae.  You could soak it in hydrogen peroxide for awhile.  Or maybe even a vinegar soak.  Afterwards, you'll probably want to cure it like the dry rock above.

[HippieSquirrel]

I’ll have to test my tap.  

1 hour ago, seabass said:

There isn't really a need to aerate the water.

The agitation doesn’t help increase the rate of leaching?  I’m assuming this occurs through dissolution so wouldn’t a powerhead help?  I’ve seen air stones mentioned as well which is why I included it but if the goal is simply movement of water that wouldn’t be the most efficient way to achieve it.  

 

1 hour ago, seabass said:

Once you're done with the freshwater cure, you should build up the bio-filter

I would be cycling like normal after setting up the tank this just trying to cut down on any chemistry issues later on.  

[Jon-Paul]

Honestly if you have three months I would do a bleach cure and then follow up with saltwater and lanthanum.

 

Basically a bleach cure 10:1 with whatever water you want to use to break up and oxidize organic matter for 14 days. Let dry then soak 2 days in RO with some Prime to get rid of the bleach followed by heated saltwater (I actually cooked the rock in water at 90F) cure for a prolonged period of time while occasionally changing the water, or/and using Lanthanum Chloride.

 

I did this method over the course of about 3.3 months and my rock (pukani) doesn't leach any phospahte. My readings in my tank are consistently below 0.1 and are usually about 0.03 but have begun to creep up with feedings. The main thing is that the rock itself isn't leeching. I have about 3lbs in a 3 gallon so it was a pretty small scale operation. During the cure I was seeing phosphates up close to .75 post bleach so bleaching alone is not enough.

 

I highly recommend the bleach/lanthanum route.

[seabass]

1 hour ago, HippieSquirrel said:

The agitation doesn’t help increase the rate of leaching?  I’m assuming this occurs through dissolution so wouldn’t a powerhead help?  I’ve seen air stones mentioned as well which is why I included it but if the goal is simply movement of water that wouldn’t be the most efficient way to achieve it.

People aerate the water for the bacteria, and/or other life.  I suppose there might be some benefit if you are relying on freshwater bacteria to break down organics.  I'm not sure that aeration has much to do with dissolution (although the addition of CO2 would).

[HippieSquirrel]

9 hours ago, seabass said:

I'm not sure that aeration has much to do with dissolution (although the addition of CO2 would).

Well if you try to dissolve a solid into a liquid mixing it generally speeds up that process if it isnt quick to being with.  I thought it might be something like that.  Not sure how fast the water clouds up but couldn’t there be a higher density of phosphate and other organics closer to the surface of the rock as it leaches which would slow the leaching of more into the water?  If the water is stagnant that is.  

 

Regardless over a long period of time it probably wouldn’t matter or would be a negligible difference in time and if I’m not able to change the water frequently enough it wouldn’t matter anyway.  

 

10 hours ago, Jon-Paul said:

Honestly if you have three months I would do a bleach cure and then follow up with saltwater and lanthanum.

Thanks for mentioning this I may try a weeklong dip in bleach beforehand now, I had forgotten this was used.  

 

Thanks for both of your input I’m feeling more confident, now I hope I can find some good rock at the fish store!  

[seabass]

Yeah, mixing helps if you are dissolving something water soluble (like salt mix); not so much for dissolving rock.  IDK, I suppose mixing helps distribute solute concentrations more quickly.  However, concentrations will still tend to move from higher to lower until it's equalized.  My only point was that aeration isn't required; however, it won't hurt anything if you do.

[Natereef]

Cure it in saltwater. At least at the end of your cure you already have cycled rocks lol. 

[seabass]

2 minutes ago, Natereef said:

Cure it in saltwater. At least at the end of your cure you already have cycled rocks lol. 

You certainly could; but if the rock is leaching lots of phosphate, it's easier and cheaper to do frequent water changes with freshwater.

[HippieSquirrel]

7 hours ago, seabass said:

You certainly could; but if the rock is leaching lots of phosphate, it's easier and cheaper to do frequent water changes with freshwater.

That’s what I was trying to avoid I’m looking at 50-80 lbs of rock so frequent water changes will get pricey.  

7 hours ago, Natereef said:

Cure it in saltwater. At least at the end of your cure you already have cycled rocks lol. 

I don’t mind waiting an extra week or two for the cycle I used turbo start on my last two tanks and that stuff works great.  It probably cycled in a few days to a week and I let it go longer just to be safe.