Drain pool using backwash

[beegee226]

I recently moved into a house with a pool containing really old water with 4600 TDS. The water is crystal clear but I want to start brand new. I wanted to drain it using the backwash, but was told this won't work once the water level drops below the skimmer (I have a single suction intake coming from the main drain and skimmer). Would it work if I attached a vacuum hose to the skimmer and leave it in the pool while I backwash?

Thanks!

 

[woodyp]

If this is an above ground pool, just take your vac hose...submerge and fill it....cup hand over one end....then throw it out of the pool. For an in ground, can't you just turn off the suction from the skimmer? You will soon discover here that we really don't place and creedence on TDS. Trust me.....you're just fine. My pool water is 10 years old mostly and never been tested for TDS. Welcome.

 

[CJadamec]

Welcome to TFP

Water is very old stuff for sure but there is no reason to throw out the water in your pool solely based on how long its been in your pool. Pools are constantly refilled due to evaporation and rainfall.

There are some reasons chemically, mainly CYA and CH would be reasons to exchange the water in your pool. TDS is not a number we would consider as a reason for water change. In the grand scheme of things TDS means very little when determining the condition of your pool water.

I'm guessing you are using a pool store to get your water test numbers. We have found thru years of data that pool store on a whole have extraordinarily poor accuracy in their test results. You can bring the same pool water to 3 different stores and get 3 totally different test results and 3 totally different recommendations on what to do with your water. So please take their recommendations with a large grain of salt. The foundation of what we do here at TFP relies on accurate water testing done by you at home with your own water testing kit.

If you have the pool store results handy post what they said.

 

[beegee226]

It is in-ground and there is not a separate shutoff for the skimmer. The poolman that serviced the pool for the previous owners said the water was over 20 years, and with the high TDS, the water tastes kinda funny too.

- - - Updated - - -

You are correct, those results were from Leslie's Pool Supply! The pool also has a salt cell that was broken, but had it replaced by the home warranty company, so I want to convert to salt water. The pool supply store said it was already high in salt at 3100 and with the high TDS of 4600, the salt level would just keep increasing until it wasn't maintainable within a couple months and I'd have to dump any way.

Thanks for your quick replies!!

 

[kairus00]

It is in-ground and there is not a separate shutoff for the skimmer. The poolman that serviced the pool for the previous owners said the water was over 20 years, and with the high TDS, the water tastes kinda funny too.

- - - Updated - - -

You are correct, those results were from Leslie's Pool Supply! The pool also has a salt cell that was broken, but had it replaced by the home warranty company, so I want to convert to salt water. The pool supply store said it was already high in salt at 3100 and with the high TDS of 4600, the salt level would just keep increasing until it wasn't maintainable within a couple months and I'd have to dump any way.

Thanks for your quick replies!!

The salt level won't increase unless you are adding salt via some method. In fact, you will probably see your salt level decrease over time from water splashing out, backwashing (depending on your filter), etc. 3100ppm of salt is a perfect level to be at for most salt water chlorine generators. If you drained your pool you would have to add all that salt back in to utilize a salt cell.

I have somewhere around 3800ppm of salt in my pool, and my salt cell works between 3000-5000pm.

 

[beegee226]

The salt level won't increase unless you are adding salt via some method. In fact, you will probably see your salt level decrease over time from water splashing out, backwashing (depending on your filter), etc. 3100ppm of salt is a perfect level to be at for most salt water chlorine generators. If you drained your pool you would have to add all that salt back in to utilize a salt cell.

I have somewhere around 3800ppm of salt in my pool, and my salt cell works between 3000-5000pm.

Yeah, the pool supply store was saying that every chemical you put in your pool increases the salt, so over time it would just skyrocket based on the TDS. I'm a total newbie, so I just accepted it as truth.

 

[kairus00]

Yeah, the pool supply store was saying that every chemical you put in your pool increases the salt, so over time it would just skyrocket based on the TDS. I'm a total newbie, so I just accepted it as truth.

If you have a salt water chlorine generator, then the only thing you should need to add to the water routinely is muriatic acid to combat pH rise. If you dose liquid chlorine, it will increase your salt levels, but you won't need to dose liquid chlorine if you have a salt cell. The one thing I would want to check is what are the levels of CYA (cyanuric acid)? It is to build up high levels of CYA and high levels are not a good thing.

Just for fun I checked my pool with my TDS meter, and it's 3360ppm. I don't think it's a very useful number though.

 

[CJadamec]

The TDS number includes the salt concentration in the the pool. TDS stands for total dissolved solids. Salt is a dissolved solid, calcium hardness is a dissolved solid, iron is a dissolved solid. You get the picture. Really all the TDS number tells you is that there is something dissolved in the water. It really doesn't help you at all in treating your pool.

That slightly funny taste in the water is probably the salt.

You should ask the old pool guy what he usesed to treat the pool and when the SWG broke.

 

[Jimrahbe]

Bee,

Did the Pool Store by chance tell you what they think your CYA (Stabilizer) level is???

Thanks,

Jim R.

 

[mknauss]

I would suspect high CH in S California. But a real test kit is needed.

 

[AimeeH]

If you have a salt water chlorine generator, then the only thing you should need to add to the water routinely is muriatic acid to combat pH rise. If you dose liquid chlorine, it will increase your salt levels, but you won't need to dose liquid chlorine if you have a salt cell. The one thing I would want to check is what are the levels of CYA (cyanuric acid)? It is to build up high levels of CYA and high levels are not a good thing.

Just for fun I checked my pool with my TDS meter, and it's 3360ppm. I don't think it's a very useful number though.

You would also need to maintain CYA in a pool using SWG.

I vote with the others experienced posters here there is no need to drain the water. You would be well served to do a bit of reading in pool school linked above and getting your own quality test kit. I love my TF-100

Also using liquid chlorine does indeed add salt to a pool. Albeit a very small amount at a time but over a long period of time that can add up.

 

[splashpad]

I recently moved into a house with a pool containing really old water with 4600 TDS. The water is crystal clear but I want to start brand new. I wanted to drain it using the backwash, but was told this won't work once the water level drops below the skimmer (I have a single suction intake coming from the main drain and skimmer). Would it work if I attached a vacuum hose to the skimmer and leave it in the pool while I backwash?

Thanks!

Welcome!

Can you add your pool details in your signature?

Are you interested in caring for the pool yourself?
Then I would recommend reading up on ABCs of Pool Water Chemistry