Does anyone know the best way to clean sandwash. My pool is just over 18months old but the surrounding sandwash terrace has hairline cracks forming in certain areas. These cracks seem to attract the dirt and have become unsightly. The dirt is just from dirty rainwater and dew. Also other areas where dew and rainwater runs off the roof of a sala, main house and outbuilding have become discolored and dirty looking. Any advice would be appreciated. Can the hairline cracks be repaired or does the whole area (big) need re-skimming. Is that even possible? Is there an easy way to clean this type of surface. I have tried a jet wash which doesn't work.

Thanks in advance

Islandape

I was going to suggest that you pressure wash it but I guess you have tried that. We just did that with ours and it came up nice and clean. Perhaps you need more pressure? We had the whole pool deck and drive way done and it looks like a new place. No advice re the hairline cracks. Seems to be a thing with sandwash.

Try an acid wash.

Splash a mix of 30% pool acid and 70% water (add the water to the acid, never the acid to the water) all over the discoloured area and scrub with a stiff bristled brush. Leave for 5 minutes then wash off with the garden hose.

Sorry but I think the rule is add Acid to Water, NOT the other way!

"Do as you oughta, pour acid into water".

The reason is mixing concentrated acid and water is highly exothermic can in some cases the amount of heat generated can instantly boil.

So if you add water to the concentrated acid the small amount of water will instantly boil and splatter hot acid all over the place.

Some acids will generate Hydrogen gas and will ignite and explode.

If you add the acid to the water, the water can absorb most of the heat and it won't splatter or explode.

Sorry but I think the rule is add Acid to Water, NOT the other way!

You could be right there... there is a lot of heat generated.

I usually do it in a 9 litre bucket... with only 500mm or so of acid in the bottom.

I'll try it the other way around next time.

Sorry but I think the rule is add Acid to Water, NOT the other way!

You could be right there... there is a lot of heat generated.

I usually do it in a 9 litre bucket... with only 500mm or so of acid in the bottom.

I'll try it the other way around next time.

Excuse my ignorance ( I use a company to maintain my pool ) but if I were to find a maintenance / chemical shop in Chiang Mai is there a particular brand of pool acid I should look for?

I think "des joyeaux" ( French pool manufacturer ) sells chemicals near airport plaza so I could look there.. Otherwise if anyone is local to me please could they suggest a place and brand of product.

The terrace runs / slopes into the pool, will any harm be done if the diluted acid mixture ends up in the pool ?

Thanks for your help so far.

Islandape.

Excuse my ignorance ( I use a company to maintain my pool ) but if I were to find a maintenance / chemical shop in Chiang Mai is there a particular brand of pool acid I should look for?

I think "des joyeaux" ( French pool manufacturer ) sells chemicals near airport plaza so I could look there.. Otherwise if anyone is local to me please could they suggest a place and brand of product.

The terrace runs / slopes into the pool, will any harm be done if the diluted acid mixture ends up in the pool ?

Thanks for your help so far.

Islandape.

Why don't you ask the pool maintenance company to do it for you?

Pay them a bit extra for the acid supply and labour, and they can check and remedy the pH balance after it's done as well.

BTW, I think the most common pool acid used in Thailand is Hydrochloric acid, HCl.

Excuse my ignorance ( I use a company to maintain my pool ) but if I were to find a maintenance / chemical shop in Chiang Mai is there a particular brand of pool acid I should look for?

I think "des joyeaux" ( French pool manufacturer ) sells chemicals near airport plaza so I could look there.. Otherwise if anyone is local to me please could they suggest a place and brand of product.

The terrace runs / slopes into the pool, will any harm be done if the diluted acid mixture ends up in the pool ?

Thanks for your help so far.

Islandape.

Why don't you ask the pool maintenance company to do it for you?

Pay them a bit extra for the acid supply and labour, and they can check and remedy the pH balance after it's done as well.

BTW, I think the most common pool acid used in Thailand is Hydrochloric acid, HCl.

That is what I shall do, thanks again for your comments.

thanx for all the advice,

but i have the same problem with my terrace and the cleaning water will go either to the pool or the garden. how will it damage grass, flowers and so on or destroy the poolwater. i don't want to loose my flowers or have to empty my pool and refill.

any suggestions or experience??

thanx

I don't have any specific knowledge here, but the idea of a coat of sealant comes to mind to deal with those fine

crack, once you have got it clean.