How To Lower Tds Form 1700 Without Draining Pool

[mogul59]

I have been seeing soap sud like foam on my pool for a few weeks. My TDS is 1700 and my Phosphates are 500. My pool guy says I nee to drain it. Leslie's says I might run the hose and let a lot go out the overflow drain. Any Ideas on this? I have an 18,000 gallon poo with spa

Hi-

I have a 27,000 gal concrete pool. Due to financial reasons I am not able to run/open my pool this upcoming season. I would like to drain my pool next month to avoid problems with west nile virus and algae before the weather gets warm. My question is this: will draining the pool for 5 months during the warm weather have any bad effects on the concrete? I know water exerts pressure on the pool wall and do not wish to have any cracks begin to appear from the lack of water in the pool. Thank you all in advance!

[waterbear]

TDS (total dissolved solids) and phosphates are useless measurements that mean little on their own. If you are seeing foaming in the water that indicates a high organic load (which can be remedied by maintaining a proper FC level for your CYA level) or possible contamination from soap or the use of certain algacides (linear quats foam and they are the most common algacide used in pools. They are actually cationic surfactants, which are a class of detergent!). Please post a full set of test results NOT done with test strips so we can get an idea what might actually be going on in your pool,. Your free chlorine, combined chlorine, , cyanuric acid, pH, calcium hardness, and Total Alkalinity and what chemicals you have recently added such as algaecides (and their ingredients) will tell us a lot more. Don't get sucked into adding phospate remover and a TDS by and of itself is not necessarily a problem. It is what the TDS consists of that can be a problem. For example, if the TDS is mostly sodium it's a non issue. If it is mostly cyanurate it can indicate an overstabilized pool and the CYA reading is a better indicator of water quality. If it is mostly bicarbonate then it can indicate that the TA is way too high and the TA reading is a better indicator. If it is mostly calcium it can indicate that the calcium hardness is too high and the CH reading is a better indicator. FWIW, high TDS is generally a non issue and is used as an 'excuse' for pool water problems when the pool person or store does not understand enough water chemistry to explain what is going on (a way too common occurrence!)

[kcolvin]

Waterbear!!

I have a similar problem. Leslie's Pool Supply us telling to drain half of our pool to bring the TDS in to check. Our pool is about 10 years old. It was a salt pool until about a year ago, when we switched back to chlorine tabs. I would really like to avoid draining the pool but its a bit cloudy and having algae outbreaks, despite the cholrine levels. We never used to have any water problems. Here is a summary of our levels. Maybe you can help!!

FAC 2ppm

TAC 2

CH 360ppm

CYA 80ppm

TA 100ppm

pH 7.8

Copper 0ppm

Iron 0ppm

TDS 3500

Pho 300 ppb

Thanks!!!

[chem geek]

Please post a question in only one place. This was already answered in your other thread.