The ratio is 1 part muriatic acid to 20 parts water. The instructor at Watson's stated the ratio should be 1/2 gallon of muriatic acid for a 35 gallon garbage can full of water. My pool store in Timonium, Maryland says that the grids should be soaked for 12 hours in a liquid of 3 parts water to 1 part muriatic acid. This is very different from the two previously submitted ratios of 1 to 20 and 1 to 70. I don't think either of those ratios are sufficient to clean the grids adequately.
Purchase one to two quarts filter cartridge cleaner. Maybe about $10 - $12 qt. and maybe you can reuse it a couple of times. Use a 32 Gal (approx.) trash can partially fill the trash can -- enough to just go over the top of the end support of the grid. Add one qt. of the cleaner. Hose the accumulated debris off the cart. to get as clean as possible using the strongest possible water pressure ( most homes do not have over 90# of water press.) Once the bulk of the dirt is removed put the grid into the trash can of solution and let soak overnight. Next day, spray with jet stream until clean or dirt stops coming off the grid assy. NEVER PUT THE DIRTY GRID IN ANY ACID SOLUTION BEFORE THE ABOVE CLEANING PROCESS. If you do you might as well throw the grid out. You have impregnated the grid fabric with any body oil, cosmetics etc and it will never come out. If after the solution above the grids are still stained you may then briefly use a very mild solution of acid and water mix to remove iron stains and such. These are only cosmetic and don't seem to affect the performance of the grid. I have done it this way for many years and my grids come out looking as nearly new. And I get a long run out of them. You only need to dip the grids in the acid solution a couple of times briefly.
THIS IS IMPORTANT: I think I can explain the disparity in the above answers with respect to the varying dilution ratios.
If you are using straight muriatic acid -- the same type that you would use to etch concrete, brick, or glass -- the MORE DILUTE ratio is probably correct. "Real" muriatic acid is about 30% hydrochloric acid, and rather dangerous stuff. (So strong that my pool guy -- even though he sells the stuff -- refused to give me verbal advice on its use. "Just read the label" he said... to limit is liability! Alas, there are no "pool filter cleaning" instructions on the side.)
He also suggested a "safer" product -- labeled "filter cleaner". This was mildly acidic, and mostly detergents. Its label suggested a 1-to-3 ratio of product to water. So I propose that accounts for the disparity reported above.
Then, back to "how to use muriatic acid": I suggest that either dilution will work, and that the less dilution you use (say 1-to-20) then the soaking time will be less.... and the more diluted solution (say 1-to-70) might be more appropriate for 12 or 24 hours. But... the exact "recipe" is something I'm still in search of...
What can you clean with muriatic acid
Muriatic acid can be used to clean dishwashers. Muriatic acid is very strong and should only be used occasionally for cleaning the dishwasher.
Extremely carefully. Muriatic (hydrochloric) acid is not something you should be messing around with if you don't know how to handle it safely.
Muriatic acid can be effectively used to clean calcium deposits, but extreme caution should be used. Only use it if you have plastic plumming, as it is corrosive to metal pipes used generally in older homes. Muriatic acid will burn skin and if it gets in the eyes, it can cause blindness. When using muriatic acid to clean calcium deposits in toilets, the results will be immediate. Your toilets will look brand new!
YES. USE ABOUT TWO PARTS WATER ONE PART ACID. LET THEM SOAK FOR A FEW HOURS THEN RINSE. Muriatic acid can be used to clean filters, HOWEVER there is a proper sequence to cleaning the filters. I am asuming you are talking about cleaning either cartridge or DE filters. If muriatic acid is used first in the cleaning process you will set the oils permanently into the filter material and ruin the filters. You MUST remove the oils from the grids (cartridge and DE) first then rinse with water. Next you can use the muriatic/water solution (1:10), then rinse again. To remove the oils from the grids or cartridges you can use a a cleanser manufactured for this purpose that you can purchase from your local pool & spa supply store or you can can use a TSP & water solution. TSP can be purchased at your local hardware store. Cartridge filters can loose approx. 20% of their capability with every filter cleaning. It is important that the filters cartridges be replaced every so often. Steve Dunn Vice President - Sales Commercial Pool Systems, Inc. Note: A 20:1 ratio (water to acid) should be sufficient for most situations. Even at this strength, it takes a lot of material (e.g. baking soda) to neutralize the acid for safe disposal.
Muriatic acid has a chemical substance that can clean toilet bowls.
Give it a week, and make sure you dilute the muriatic acid.
You can by a "filter cleaning" chemical at your pool store. It usually requires you to soak the filter in part water and part chemical for 12 hrs or so and then spray with hose. It works great on our hayward cartridge filter.