Vinegar, NO, how about Acetic or muriatic acid?
 

When my tank is finally empty, I was thinking about cleaning it all out (overflow, plumbing, pumps, skimmer, etc...) by running vinegar through it for a few days.

Obviously 330 gallons of vinegar is a little costly, so I was thinking about using more pure acetic acid, and mixing to a 5% ratio (vinegar is just that, 5% acetic acid).

That is all good, but I cannot find acetic acid locally, or more specifically where to look. Any ideas?

I can get muriatic acid locally (pool supply places). Will that work? Will it harm anything?

I know Muriatic is Hydrochloric acid. I use it for eating aluminum and removing the Galvanized coatings of of metals. It will leave a residue and most likely render the tank useless.

Why not just a really diluted vinegar? I would think 5-10g in freshwater would loosen up the coraline after a few days

1L of vinegar with 50 gallons of warm water left circulating for 1 day does a wonderful job of cleaning deposits out of my SW mixer even though that is an extremely dilute mix of acetic.

Vinegar comes in different strentghs, get the bottle for household cleaning. I get it at Save on foods.

Ben
I use muriatic acid on regular basis for cleaning my pumps/calcified equipment. I don't see any problems as long as its diluted. if you have a pH meter, maybe just add enough to bring the pH down to 4. u'll probably have to add a bit more throughout the day to keep it at 4.

Well, thats re-assuring for sure. :D

I believe JL's used to sell the crystalized muriatic acid to clean clacified pumps and hardware. i can't find it on their website now but it was highly effective.

Ya, it worked really well. They used it in-store too. I can't remember what brand it was called or the dosing amount.

warm water when you clean with vinegar...use a heater

Randy at RC says to use the muriatic acid. Way stronger then Acetic, but with less added it obviously has less buffering capacity, so I may need to add more as it eats up coraline and stuff.

Boy my house is gonna stink!

Remember, add acid to water, not the other way around. and neutralize it before disposal, a few boxes of baking soda should do it.

WAYYY off on a side note, there's many literature about adding vinegar to kalkwater to saturate the cal/alk levels. Does the same benefits apply with HCL?

Scrapped off a ton of coraline, maybe 4 or 5 lbs (not kidding either).

Tank is full of tap water now, added about 1 liter of muriatic acid to tank, ph dropped to 2.4. (330 gallons of system water). Within 30 mins ph went up to 2.8, added another liter. Then after a few hours added a few more liters. Ph is now at about 2.2. Not sure how low I should go, I will watch it over the next little while, see how it is tomorrow.

So far we cannot smell it in the house, but the skimmer is going crazy!

FWIW I bought 40 liters of muriatic acid.