Bought some chemicals for our new pool

[Charlize]

yesterday we went to the pool shop and bought "ph minus". it consists of "sodium bisulphate", what is this? i was expecting muriatic acid, but they didnt have this.

we visited the chemistry shop and bought some chemicals, soda ash etc. we also found this:

calcium chloride, it says 74% min. flake. is that ok for getting the calcium up? is is a powder that one must be careful with, or is it safe? i need to add like 10kg (my CH level is 90).

 

[Guest]

Stole from Wikipedia (!):

Sodium bisulfate is used primarily to lower pH. For technical grade applications it is used in metal finishing, cleaning products, and to lower the pH of water for effective chlorination, including swimming pools. Sodium bisulfate is also AAFCO approved as a general use feed additive, including companion animal food. It is used as a urine acidifier to reduce urinary stones in cats. Sodium bisulfate is considered GRAS by FDA and meets their definition of a natural product. The food grade product meets the requirements set out in the Food Chemicals Codex (FCC). It is denoted by E number E514ii in the EU. Food Grade sodium bisulfate is used in a variety of food products, including beverages, dressings, sauces, and fillings. It is also widely used in meat and poultry processing and most recently in browning prevention of fresh cut produce.

 

[PaulR]

Sodium bisulfate aka "dry acid" works fine for lowering pH. Muriatic is preferable because it doesn't have any extra stuff in it; the bisulfate has, well, sulfur. You could ask around for hydrochloric acid, the chemical name for muriatic.
--paulr

 

[polyvue]

My understanding of why it is not desirable to use pH minus (dry acid or sodium bisulphate) in pools with an operating salt water chlorine generator (SWG) is because the sulphur negatively affects cell performance. My Goldline SWG's documentation explicitly cautions against using dry acid to reduce pH. They advise the use of muriatic acid (MA) only.

 

[Charlize]

ok, this means i will not use the ph minus because i have an swg. i will ask for hydrochloric acid.

any advice on the calcium? i guess as nobody mentioned that part, its ok to add it and its not a dangerous substance.

thanks for the advice, great info!



EDIT: i just opened the calcium bag, and its not powder, but flakes. i dont know if this is important but i thought its good to mention it.

 

[chem geek]

The Calcium Chloride is probably fine to use as a Calcium Hardness (CH) increaser since this sounds like Dowflake. The flakes may take a little longer to dissolve than powder, but is should still dissolve. The two products you can use to increase CH are Dowflake (which is a dihydrate form of calcium chloride, so not as pure) and Peladow (which is an anhydrous form of calcium chloride so is more pure).

 

[duraleigh]

Can you post test results?

Are you lowering pH because you know it is high?

Sounds like you are fine with CH but your first concern should be pH and then FC and then CYA.....do you know what those are?

 

[Charlize]

ph is around 7.8-8. FC is around 4. i just added 3 kg of calcium. water is crystal clear, not had any problems thus far. CYA is around 40. will get it up gradually by using trichlor. seems my FC is quite stable, i guess its because of the swg.

i will order muriatic acid tomorrow. Should we avoid swimming until the ph is down a bit?

 

[frustratedpoolmom]

You may find high PH to be irritating, but if it's 7.8 I don't see why you can't swim.

 

[duraleigh]

Yeah, I'm with FPM....go swimming!

pH of 7.8 is normal. 8.0 starts to get out of normal. I have swum in 8.2pH in my pool and couldn't tell any difference......however, that's too high in the long run and can lead to some other issues if you leave it that high for an extended period.

Can you not find CYA by itself? Pucks (trichlor) are reasonably innefficient because you have the swg. You are correct it will eventually raise your CYA over weeks but you'll have to adjust your SWG for the added chlorine the pucks put in and then adjust again when you stop using the pucks.