About to get an RO

[dariushd]

Just finished my Taylor testing. I am RO filtering the pool today, here are the readings before the RO:

FC: 1.6
pH: 7.9-8
TA: 175-80
CH: 600 (my tap water is about 80)
CYA: 240
Saturation Index 1.05

Once I get the post RO results in a day or two, I'll post. I know I should SLAM the pool after the RO since I get recurring yellow algae on the side of the pool in the shade even after a few days of brushing (also my CYA is way high), my question is: Should I get my CYA up to 30 or so FIRST before SLAMming or should I SLAM as soon as the RO is done?

 

[duraleigh]

Go to 30 ppm CYA, then SLAM.

 

[dariushd]

Go to 30 ppm CYA, then SLAM.

I tested the water coming out of the RO filter, and the CYA in that cleaned water is about 70. That's when it first started filtering the CYA levels of 250 or so. I do hope 24 hours more and it goes lower in the cleaned water than that. I was expecting close to 0 to come out the clean end of the RO filter, seems to be capturing about 2/3 of the CYA right now, which is better than nothing, but I wonder if my pool will even get down to 30 at all.

I have to say the water coming out of the RO is super soft feeling, so it's getting the TDS and CH/TA already down really well.

 

[dariushd]

RO is a complete success. Now let me know where to go before SLAM (I'll read on how to slam of course) if anything:

TA 60
CH 70
pH 7.7 but I'm not sure, it took barely one drop of the acid demand for it to fall to 7.4
CYA 30!!!!

should I get TA and or CH up before SLAM? It's a plaster pool, I should get CH up to 250? And what's the best way for that?
got 12 hugs of 10% low chlorine ready for SLAM.

 

[triptyx]

TA is great at 60. You'll want to increase CH for sure, but don't let that hold up your SLAM - you don't want to have a perfectly calcium'd green pond.

From Pool School - Recommended Pool Chemicals :
Calcium hardness can be raised with calcium chloride or calcium chloride dihydrate. They are available in some areas as Peladow, Dowflake, Tetra Flake, or Tetra 94, often sold as a deicer by hardware stores, and some big box stores, in colder climates. Pool stores will carry either calcium chloride or calcium chloride dihydrate under a variety of names, including Hardness Plus, Balance Pak 300, Calcium Hardness Increaser, etc. Calcium products should be spread across the surface of the deep end of the pool.

PoolMath will tell you how much you need.

 

[needsajet]

You can reduce your total bleach requirement by taking your pH down to 7.2 before you start the SLAM. Also, take a minute to print out the SLAM instructions and follow the written instructions to the letter. That's the best way to get it down quick and at lowest cost/hassle.

Congrats on the RO effectiveness! Do you know how much water was replaced?

 

[dariushd]

You can reduce your total bleach requirement by taking your pH down to 7.2 before you start the SLAM. Also, take a minute to print out the SLAM instructions and follow the written instructions to the letter. That's the best way to get it down quick and at lowest cost/hassle.

Congrats on the RO effectiveness! Do you know how much water was replaced?

I'd say it probably required 15% new water, and it ran for about 54 hours, cycling through 25k just over twice at least. So I probably put in 7.5k gallons new water maybe. I needed an 85% drain to get down from CYA240+, so that saved a ton of water and stress on my plaster, but was probably twice the cost of new water here in LA. I'll be installing the Liquidator and leaving my offline puck feeder off to see how the Liquidator does. Seems an easier way to go over the Stenner pump solution.

I started the SLAM already with a pH at around 7.7, so we'll see how that goes, I'm at 12.5ppm for FC right now, and I'll keep it there for the entire SLAMming. Hopefully it'll be just a couple days, but I'll be so happy to stop seeing that ****ed yellow algae creeping up the shady part of my walls again. To be sure, once I'm done with the SLAM, I'll do 24 hours at the mustard algae SLAM level of 19 as recommended, and then let it come back down to 3-4 FC, and then Liquidator install to hopefully be able to maintain that level.

- - - Updated - - -

TA is great at 60. You'll want to increase CH for sure, but don't let that hold up your SLAM - you don't want to have a perfectly calcium'd green pond.

From Pool School - Recommended Pool Chemicals :
Calcium hardness can be raised with calcium chloride or calcium chloride dihydrate. They are available in some areas as Peladow, Dowflake, Tetra Flake, or Tetra 94, often sold as a deicer by hardware stores, and some big box stores, in colder climates. Pool stores will carry either calcium chloride or calcium chloride dihydrate under a variety of names, including Hardness Plus, Balance Pak 300, Calcium Hardness Increaser, etc. Calcium products should be spread across the surface of the deep end of the pool.

PoolMath will tell you how much you need.

Will raising the CH also raise my pH and TA? Will I need to respond with Muriatic acid to keep pH steady? I'll be shooting for 7.4 eventually once I've finished my SLAM.

 

[needsajet]

CH won't affect your pH. Good luck with the SLAM. You have a great understanding of TFPC and thanks for sharing your RO results!