Bleach vs Acid

I do not have any specific suggestions on removing the residual bleach, but I do not think it is an insurmountable problem. It will be very good at removing organic tissue that you mention.

Acid alone may be adequate in many cases, especially if the ultimate goal is phosphate removal and not copper removal. :)
 
I don't want to hijack the thread by any means but I'd like to pass on my experience for others to learn from.

I have about 400lbs of dead dried rock from BRS and the rock was surprisingly encrusted with a quite a bit of dead dried debris. I cured the rock by typical means for about eight weeks. That consisted of temps around 90 strong skimming, stong circulation and some water changes. After about the third week I also plumbed in my large bin in which I'll be growing macroalgae (about 60 gallons). I then grew some chaeto which started as about a football size clump and grew to fill the entire bin in about a week. The chaeto then continued to be pruned down to about 2-3 football sized peices every week and filled up the bin by the end of the week. After about eight weeks the rock looked much better with only some dark areas and spots of old sponge stuck in the nooks and crevices of some peices.

I was initially content with just leaving the rock the way it was and let the tank cycle as well as a good CUC take care of the rest of the debris on the rock. After reading this thread I was really intrigued and wondered if a bleach bath or muriatic acid bath (or both) would remove that remaining organic waste. I was really hesitant to use the bleach becuase I don't want to spend a boatload of cash on a large amount of chlorine neutralizer (400lbs of LR). I suspect a muriatic acid dip will neutralize the bleach, with the side effect of the production of chlorine gas, but I haven't gotten any confirmation of that. I'm sure that's because you guys don't want to suggest that then have a dozen people die from chlorine gas inhalation after reading this thread. Entirely understandable! Regardless, the suggestions provided for neutralizing the chlorine weren't appealing to me so I thought I'd give the muriatic acid a try.

To say the least, the result was spectacular. The muriatic acid essentially dissolves the outler layer of rock thus loosening any material it was attached to. I must say, MURIATIC ACID IS VERY DANGEROUS!!! I accidently dripped some on my concrete basement floor and it started eating a hole in the floor (it looked just like the acid dripping from the monsters on the movie Alien. It was yellow and bubbled while it was eating through the concrete - it was actually kind of cool). I'd hate to see what it could do to a persons bare flesh. To protect myself while working with it I used nitrile gloves and was very careful and cautious (espescially after I saw it dissolve my floor!).

I started with a ratio of 1:10 muriatic acid to RO water. After the rock was added it bubbled and reacted vigorously with lots of bubbles for about 20 minutes. After that initial 20 minutes it didn't appear to be doing much more. Once it was done bubbling and the rock still wasn't clean, I added some more acid to the solution and it bubbled vigorously again for about 20 minutes. After that point it seemed to be really loosening the organic debris but there were still some dark brown areas that looked like they could use some work. I decided to leave the rock in the remaining solution overnight. Obviously once it's done bubbling it is still dissolving the rock because in the morning a large amount of the rock was dissolved. Needless to say, all the organic material was easily cleaned off with the use of a powerhead in some fresh water (with a bit of baking soda to neutralize the remaining acid). After leaving it overnight there were parts of the the rock that were initially about the size of my fingers that were dissolved down to 2-3mm little sticks. I'd say leaving it overnight likely dissolved about 1/3 of the rock. After the second addition of muriatic acid the concentration was approx 1:6 or 1:7.

Today I did several more buckets of rock and the result was spectacular. With a few hours of a dip in the acid (1:10 concentration) there is enough of the outer layer of rock dissolved that the organic material blows right off with the use of a powerhead in the freshwater clean off area.

After seeing how much brown debris has come off this rock I'm absolutely astounded!! If I hadn't done these dips, I have no doubt this rock would have leached back in a lot of organic waste and would have led to a long ordeal of dealing with po4 leaching from the rock. I can now confidently say the rock is CLEAN!!

I give the muriatic acid dipping an A+, but it SERIOUSLY needs to be given a spectacular amount of respect and care when using it. I'm glad I didn't use the bleach since the acid did a spectacular job at allowing the organic waste to flake off as the acid dissolved what it was attached to.

Thank you everyone for the spectacular input on the this thread!!

Jeremy
 
Did a bunch more rock last night and it's turning out great. If I would have known about this 8 weeks ago I would have entirely skipped the standard means of curing the rock. Since it was dried there was no life I was trying to save anyway.

For those of you wanting to entirely clean the rock and kill everything, I have no doubt that the muriatic acid will be more than enough. The bleach would just be extra unnecessary work IMO. I can't imagine any common pests (mojanos, aptasia, FW's, bubble algea, HA, etc...) that wouldn't be killed by the muriatic acid. In addition, the muriatic acid dissolves what it is attached to therefore it is easily removed with a powerhead in the cleaning freshwater dip.

I'm all for the muriatic acid! I've taken a few peices of what were my cleanest rock and done the muriatic acid dip and the brown gunky water is enough evidence for me to know there was still a fair amount of waste material within the rock crevices. A second muriatic acid dip on the same rock ususally comes out pretty clear indicating that it isn't just the rock dissolving that makes the water brown, it really is organic waste from the outer surface of the rock.

Quick question:

During the muriatic acid dips, is the massive bubbling a chemical reaction that releases co2?? I suspect so since my tank (which is in the basement where I'm doing the dips) had a pretty significant pH drop over the last few days.


Bit of warning:

When trying the muriatic acid dips for the first time keep in mind that as soon as you put the rock in the solution it won't just bubble a little - it foams like crazy. I used 5 gal pails and filled them 2/3 full of 1:10 muriatic acid mix and when I put a few peices of rock in it raised the water level by about 2-3 inches but it bubbled so much it overflowed foam for about the first 10 minutes. I soaked it up with paper towel the used some baking soda on the concrete floor to neutralize the acid and it seemed to be OK. From now on I'll be using far less volume to start with to prevent any major overflows.

Jeremy
 
During the muriatic acid dips, is the massive bubbling a chemical reaction that releases co2?? I suspect so since my tank (which is in the basement where I'm doing the dips) had a pretty significant pH drop over the last few days.

Yes. Same as cleaning pumps and such in muriatic acid:

CaCO3 + 2HCl ---> CO2 + CaCl2 + H2O
 
quick question. I just bleached then acid dipped my rocks. I wanted to kill blue clove polyps that had spread like wild fire. Can I just reseed the rock with a new bag of the live sand Im going to use? thanks
 
The bagged live sand I think you are refering to is nothing more than a bag of bacteria if you're lucky. The bacteria will come on their own. You could always get some sand or rock from another person tank or the LFS to seed some higher organisms.
 
OK, I just want to get these rocks to cycle as quick as possible since all my livestock/corals are still in the tank running w/o any rock at all. Its a nano so only about 20 lbs. of rock. So I'll pick up a couple lbs of rock at my lfs. So should I not use a new bag of live sand to help? Im going to be buying new sand anyways.
 
The bagged live sand is pretty much useless, in my opinion. I don't think it'll add enough bacteria of the right type to be worth any extra money. A small piece of live rock might be more appropriate.
 
I got a newbie question.

Once your rock is cleaned with bleach/acid and you're ready to seed the rock with live rock...how can you know that the live rock itself will not contain any pest algae? Which leads me to another question....usually when you buy live rock, the norm seems to be to just let it go through a curing cycle and then place it in your tank...right?
 
Any live rock might contain some pests. You can use some fish food or raw shrimp to add a food source, and the bacteria that are needed for filtration will show up on their own, if you want to avoid as many problem organisms as possible. The process might take longer that way, but it will work.
 
Sean04 - my belief is that bleaching LR similar to whats posted here should kill off absolutely any pest algae...enough belach should kill and remove any live organic material IMO.

As far as seeding, follow what bertoni says.

After reading up on this so much, going forward I will always follow an approach recommended many times here on RC: any LR I buy going forward will go through this bleaching process so I can be sure it's at a certain "baseline" before I put it in my tank. As long as my tank has live rock already in it, I would expect it to become live eventually. I dont think I'll ever put LR from another tank/LFS into my tank again, and that just my opinion.
 
Sean04 - my belief is that bleaching LR similar to whats posted here should kill off absolutely any pest algae...enough belach should kill and remove any live organic material IMO.

As far as seeding, follow what bertoni says.

After reading up on this so much, going forward I will always follow an approach recommended many times here on RC: any LR I buy going forward will go through this bleaching process so I can be sure it's at a certain "baseline" before I put it in my tank. As long as my tank has live rock already in it, I would expect it to become live eventually. I dont think I'll ever put LR from another tank/LFS into my tank again, and that just my opinion.

One thing I can add to this is also be sure you stock your tank with what you really want. I put in a small frag of blue clove polyps because the girlfriend thought they were cute. Now Im using bleach and acid to kill off all my rock. xenia is another one that can get crazy
 
Thanks for the info.

Just one more thing...if I do this method and my tank is a new tank, how will I get the live pods and other critters that I need to grow in my fuge?
 
Giving this a try.

1. Filled a 40g brute can with rock.
2. Filled it with the hose.
3. Added 3 gallons of bleach.

-- have already done the above today, will do the below --

4. After 24 hrs, drain the water out.
5. Refill with water.
6. Add dechlorinator. I don't think I have enough prime (1 small bottle) but I'm going to use it anyway.
7. Add 3g muriatic acid.
8. Wait 30 minutes.
9. Add excess baking soda to neutralize.
10. Drain.
11. Rinse the rock very well.

Do these steps all seem ok? Is 30 min in the acid bath enough? Will the acid neutralize whatever bleach might be left?
 
That looks like a mostly reasonable approach to me. I'd probably be careful with the bleach, and do a major rinse or two, followed by the dechlorinator. The acid will combine with the bleach to form chlorine gas, which is quite dangerous.
 
I am doing this outside, but will still be extra careful with the acid after the bleach. An extra rinse or three certainly won't hurt.
 
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