Potassium Permanganate to sterilize entire system

[terahz]

Hi Chemists,

I've just rebooted my tank and want to make sure absolutely nothing from the previous setup survives. I've washed the glass and sump with water and vinegar solution (1:1), but can't clean the pipes.

A fellow reefer suggested running a high concentration of Potassium Permanganate which can be later neutralized with Hydrogen Peroxide. The other option would be regular bleach + sodium thiosulfate for neutralization.

The system is already setup with salt water, sand and base rock. Nothing is alive in it (except whatever is left in the pipes from the system before the reboot).

What do you think?

 

[disc1]

Regular bleach should be plenty effective.

 

[slickmin]

Bleach kills all

 

[terahz]

Bleach will work, yes, but it is easier for me to find Hydrogen Peroxide and Potassium Permanganate than Sodium Thiosulfate.

From my limited reading the "leftovers" from PP + HP are MnO2 (which is not water soluble?) and potassium, which should be fine, given that some people even dose it.

Ideally, I just want to treat the entire system as it is, without having to take out rock and sand, do a 100% water change (or close to that) and introduce some live rock to start the seeding process. Is that doable?

 

[skunkmere]

you could get some chloirine test strips to see when you are free of chlorine. the other way sounds expensive and too complicated. i work in a clinical setting and we use bleach and rinse it away. the devices we use come in contact to the patients blood. any trace of bleach would be deadly.

 

[disc1]

Sodium Thiosulfate is the stuff in any regular tap water conditioner or dechlorinator.

Not hard to find at all.

 

[skunkmere]

are you going to stir you sand? how deep is it? i would think it would take a long time to clear.

 

[terahz]

you could get some chloirine test strips to see when you are free of chlorine. the other way sounds expensive and too complicated. i work in a clinical setting and we use bleach and rinse it away. the devices we use come in contact to the patients blood. any trace of bleach would be deadly.

I remember reading on RC someone (boomer?) saying that commercial bleach will not go away on its own in water. I'm sure you guys use it and then dry the surface, which is probably ok. That being said, I have a gallon of bleach sitting next to me...

Sodium Thiosulfate is the stuff in any regular tap water conditioner or dechlorinator.

Not hard to find at all.

Water conditioner you say. Let me check... I have API stress coat (Sodium thiosulfate, Aloe Vera) and Aqueon Water conditioner (Sodium thiosulfate, disodium EDTA, sodium carbonate, polyvinyprobollidones), so it looks like I already have it. Now the next question becomes, how much of each to use, since they don't say how much sodium thiosulfate they contain...

are you going to stir you sand? how deep is it? i would think it would take a long time to clear.

The sand is about 1.5" and I will either stir it, or leave the solution run for a very long time.
As for clearing, are you referring to the bleach or PP?

 

[birddog486]

Go with the bleach. The PP will leave a brown scum and stain when it's spent.

 

[disc1]

Go with the bleach. The PP will leave a brown scum and stain when it's spent.

Yes, MnO2 can be hard to clean up because it's not soluble.


When hypochlorite (bleach) stays in solution for very long it will eventually react with something to oxidize it and make chloride, or it will react with itself to form either oxygen and chlorine gas, or chlorate and chloride. Chlorate is toxic, but won't live long. It is a potent oxidizer and will eventually end up being chloride or chlorine one day.

Sodium hypochlorite (household bleach) is unstable when it's not dissolved in water. It will spontaneously react with itself to create the same products as above, neutralizing the harmful effects. So once you bleach out the system and drain it and let it sit for a day or two, there will be no residue. The small remaining pockets of water in the system may hold some, but the amount should be insignificant. If you're really worried about it, add the tap conditioner like you would for tap water and you can rest assured that it's all neutralized.

 

[terahz]

Thanks guys. Bleach it is.

So the official ratio for cleaning with bleach is 10:1 water to bleach. Minimum (ss per CDC) for sanitation is 50:1, so I'm planning to use one gallon of bleach in my ~50G of water. Will let the system run like that for about a day and drain it tomorrow evening.

I assume, after I'm done draining the system, I'll probably have about 1G of water in the sand so when I refill the system I'll treat it with some of the water conditioners as though I'm treating 1G of tap water.

Hopefully that will do the trick.

 

[disc1]

Thanks guys. Bleach it is.

So the official ratio for cleaning with bleach is 10:1 water to bleach. Minimum (ss per CDC) for sanitation is 50:1, so I'm planning to use one gallon of bleach in my ~50G of water. Will let the system run like that for about a day and drain it tomorrow evening.

I assume, after I'm done draining the system, I'll probably have about 1G of water in the sand so when I refill the system I'll treat it with some of the water conditioners as though I'm treating 1G of tap water.

Hopefully that will do the trick.

You can always add more thiosulfate based water conditioner than you need. Within reason of course, but it would be no problem to go ahead and treat the tank as if it were 50 gallons of tap. Or even 100 gallons.

I don't know about bleaching the sand. You might be more concerned with the dead stinking corpses in it than you are with the chlorine. If it has bacteria or any higher life in it, there's going to be a ton of phosphate and nitrate after it's all broken down by the bleach. At least take it out and rinse it really well.

 

[terahz]

Sand was new/dry. I really hope there was nothing alive in it. I should have done the bleaching before putting the sand and rocks but it is too late now .

The only real reason I'm doing all this is to clean the plumbing and I'm happy I decided to, because after 10 mins of running I can already see crap floating around.

 

[disc1]

You should pull out as much of it as you can. Definitely pull out the rocks.

If you can't do that, then I think the risk there may not be worth the reward of the bleach. Most all of the things you might worry about contaminating your tank aren't going to be able to live dry. So if the tank has been dry for some time, there may be no need to run any bleach through it.

 

[disc1]

While sodium hypochlorite is unstable when dry and will go away, calcium hypochlorite if it forms in the sand will not. Calcium hypochlorite is perfectly happy to wait until you add water again to come back out.

 

[terahz]

That's alright, it is too late now .

So here is the plan for tomorrow evening:
Darin bleach solution as much as possible. Rinse sand with a little bit of hot water in tank. Darin. Repeat last 2 steps. Rinse rocks with hot water. Add some water to tank and treat with water conditioner. Stir sand. Drain. Add NSW.

I'll try to find some chlorine strips and test at the end. If chlorine is detected, I'll just treat again until it is gone.

Talk about doing it the hard way...

 

[bertoni]

You could just cycle the tank, as well. It'd take longer with the bleach, but it'd be consumed eventually. Just add a bit of organic material from time to time.

 

[terahz]

Yep, I will cycle it one way or another.

On a side note, I couldn't stand the bleach/chlorine smell so I drained everything. It sat there good 3 hours. At 500ppm concentration, if anything survived, it deserves to live! Sump is padded dry, walls of tank dry, and by clearing a corner of the tank from sand, I'd say there is less than 1/2 G of water/bleach solution left in there (There is barely a layer of liquid on the floor, just all the sand and rocks are wet). I'll let it sit like that for the rest of the day and resume the cleanup after work.

1/2G at 500ppm, after a rinse with at least 1G water should hopefully bring the concentration to less than 250ppm. When diluted with 50G NSW should become ~ 2-3ppm. Assuming the water conditioners I have are for 0.5ppm, I'll just dose 6x for 50G and start adding some organic stuff to induce a cycle.

Thanks guys.

 

[terahz]

Well I figured I should just report what ended up happening to bring the thread to a closure.
After I poured the bleach (about 1.4G in ~50G of tank water) about two hours later I couldn't stand the smell, so I drained everything. I made sure there is no water at the bottom of the tank and sump. 15hrs later (only the sand and rocks were damp) I did 1.5G RODI water cleaning of the sand. Water drained. Another 1.5G of RODI plus about 100ml of aqueon water conditioner (dose was 5ml per 10G of water). Let it sit for about 1 hr. Water drained. Just finished putting the 50G NSW I've been making since yesterday night. Also added about 40 more ml of aqueon's water conditioner and that's it. Sprinkled a little bit of food in there and will place a couple of live rocks from fellow reefers on the weekend.

Thanks to all for your help.

 

[bertoni]

You're welcome! Good luck!