significance of TDS and phosphate

[frogboy]

I have the TFP test kit and noticed the pool store also measured TDS and phosphate (he said both were ok and the water was in good shape). Numbers were
pH 7.6
FC 5 (I just replaced my SWG and am in the process of titrating the chlorine production %, he said this should be between 0.7 and 3)
TA 90
CYA 70
Phosphate 250? (can't recall exactly but it was the 2nd lowest of the 4 color blocks)
TDS (don't know the number but he said it was fine)

When I've measured calcium hardness it's been 975 or so and draining the pool was recommended here. He said that he wouldn't with a TDS number coming back as normal. What are your thoughts about this? Thanks!

 

[Donldson]

Let me put it this way regarding TDS: if you have 3000 ppm of salt, is that ok? What if you have 3000 ppm calcium? Both examples will have the same TDS, but one is normal for an SWG pool and another is a massive problem.

TDS is a pointless measurement, you need to know how much of each thing is in the pool not the total. That the guy ignored the very elevated CH level because he didn't think the TDS is bad is a major red flag as to just how bad their advice is. The phosphate reading is quite low so kudos on him for recognizing that, but it's not a level worth tracking.

 

[PoolStored]

When I've measured calcium hardness it's been 975 or so and draining the pool was recommended here.

I would, just to avoid the CSI dance required to avoid scaling on the pool surface and in the salt cell.

I wouldn't drain, I'd do a no drain water exchange...here:

Draining - Further Reading

www.troublefreepool.com

 

[frogboy]

I believe my pool was installed in 2003 (according to the permit history). Can you tell if this is a plaster pool? Any tips on what can be done about the staining on the bottom? If it needs to be drained anyway, does it make sense to try to fix that at the same time? The water is clean and clear thanks to you guys but because the bottom is discolored it doesn't sparkle like a new pool does...

 

[PoolStored]

Plaster pool.
Not sure if that is mottling from age or staining.
Try identifying the stains.

Stains in Your Pool

The stained pool is beyond embarrassing. Our in-depth Guide to remove stains in your pool will help you to remove the stains and prevent them in the future.

www.troublefreepool.com

 

[ajw22]

Stain ID Kit | Jacks Magic

jacksmagic.com

 

[proavia]

You have a TF-100 Salt test kit.
Pay zero attention to the pool store tests - post a full set of current test results from you own test kit.

FC
CC
pH
TA
CH
CYA
Salt
Water temperature

Be sure you are taking the TA and CH tests to their end points.
See the extended test kit instructions.

Extended Test Kit Directions Archives

www.troublefreepool.com

Use the FC/CYA Levels chart to determine the correct FC range based on your CYA.
Use PoolMath to log your test results and determine correct dosing.