Acid Washing - Drain vs No Drain??

[GeordieLaforge]

Our gunite pool is 12 years old and has tan staining on the walls and bottom and
probably should be acid washed. Of course, this normally means draining the
pool (and the water table is high right now) and paying about $800 to a local
pool company.

I have also heard of the No Drain system which lowers the PH, then you keep
brushing the pool until it's no longer stained, then raise the PH and restart
the equipment and vacuum the stuff out. This system is (I think)about 1/2 the
price though I have to do all the work vs a pool company.

So...what are your ideas on both...? Or any other suggestions? The pool is a free form, approximately 28,000 gallons, with a cartridge filter system.

Larry
Memphis, TN

 

[JasonLion]

Welcome to TFP!

A no drain acid wash is a lot less expensive than a regular drain and manual acid wash. However the no drain approach doesn't give you any control over the process. Good plaster is almost always removed in some areas along with the scale. There is also a risk to the equipment, especially pool heaters (if you have one). A full drain and manual acid wash give you control over where acid is applied, so you can limit it to only remove scale.

 

[GeordieLaforge]

We do have a pool heater but I assumed that all the equipment is turned off during the process until the PH is raised back up again. I'm guessing that attempting to acid wash (drained) myself would not be advisable since I don't have breathing equipment (I did when I was a volunteer fire fighter but no longer!) plus the hazards of dealing with the acid? We should have pretty good plaster all the way around since it's never been acid washed since we built the pool in 2000.