Cleaning a Used Tank...opinions wanted

[Hoss]

Hey guys. Just bought a 120 gallon and need to clean it up. It has two overflows and there is gunk and nasty stuff that I can not reach. Would it be ok to fill this tank up with water, add 1-2 gallons of muriatic acid to it and let it sit for 24 hours?

I'd leave it in my backyard. Where can I safely pump the 120 gallons of water/acid?

I thought about Vinegar/Water solution, but that would take too long and would require too many gallons of Vinegar (I think). I clean all my equipment with vinegar, but I'm thinking muriatic acid is the way to go here.

Thanks all, I'll start a build log in the next few days.

Hoss

 

[melev]

If you do that, make sure you have a pump moving the water and acid all the time, or it will separate and settle to the bottom.

Where to dump it is a good question. What part of your property do you not care about? You can always dump it down the toilet, but don't drip it on anything on the way to the bathroom. It will bleach concrete too.

That being said, I use it myself. I just dump it on an area of dirt I don't care about.

 

[Tinyfish]

Just be careful. I wear a really good cartridge filter mask when using it. And it will eat your clothes and anything steel will rust.

 

[Hoss]

What concentration would you guys recommend? I was thinking two full gallons of muriatic acid with the 120 gallons of water. Also, should it sit overnight, or will I see when it has done it's job and can start emptying after a few hours? Thanks.

 

[Guest]

i would do couple of gallons of vinegar first if that doesnt work then add muriatic acid just to let you know muriatic acid is another name for hydrochloric acid so you need to be very careful with that stuff pretty potent so i would try not to splash it and if you can where eye protection and gloves.

 

[malofish]

I bought two tanks that were dirty, i mean dirty!! I used a cheap spray bottle, vinegar, and a few sharp razor blades to clean the glass. I dont know if this will work for overflows or not.

 

[Rick]

@Hoss wrote:

If you do this I would put in one gallon to begin with. Make sure you have the tank filled with water first before you add the Muriatic acid. Never add the acid to an empty container and then add the water to it. If you add one gallon and you see bubbles coming off of the coraline algae or other crap, you will know the Ph is low enough. Then you could add a little more if you need it. I know I can add 1 gallon to my 30,000 gallon pool and it will lower the Ph. If you only need one gallon then you will more easily be able to add more water to the tank as you drain it to dilute the solution and have it be safe enough to run down a drain or down the driveway.
As Marc said make sure you have a pump or powerhead circulating the water while it sits over night.

 

[Hoss]

I think what I am going to do is spray everything with a highly dilluted muriatic solution and start scrubbing. I'll let the solution sit on the overflows for a while. If that does not work, I'll fill the tank and let it sit.
My biggest concern is actually with the overflows. Not the coraline on them, but the gunk built up inside them. These oceanic overflows have a small gap between two pieces of plastic and that is pretty cruded up. I was thinking about taking a coat hanger and just try to knock out as much as I could.

Thanks for the suggestions.

 

[melev]

I believe a section of the overflow pops off to get access to clean it.

If you want to reduce the amount of water used, you can lay the tank on its side, and fill up just enough water and acid to create a water layer over that surface. Wait 20 minutes or until it stops bubbling, and scrape it with gloved hands. Once done, rotate the tank carefully to move the solution to the next panel in question. Repeat until you have all four sides done.

The only way to do those overflows with minimum liquid would be to tilt the tank at a 45 degree angle, putting something under the front lip to keep it stable. I would put the back edge on something soft like padding or your lawn so there aren't any pressure points. Now you could fill the tank maybe 1/3 instead of the full 120g to soak the overflows.