First water drain & replacement - any other preventative maintenance?

[ndnile]

I plan to drain my pool in the next 24 hours to solve my CYA problem of 280 ppm due to puck drama from previous owners. While the pool is empty for a short period, is there any other preventative maintenance that I should perform?

I am already scheduled for bead blasting my calcium silicate on the waterline tile that I'm told is a result of the volcanic past of our fill water (Hawaii). It was suggested that I acid wash the one inch square tile that makes up the pool, and I've also been advised to consider skim coating the grout. I'll have to read the forums more, as I'm not familiar with how (or when) to do either.

Test results from Taylor K-2006
FC: 12, CC: 0
pH: 7.0 (never seen higher than this, though my previous pool tech always read 7.4)
TA: 90
Ca hardness: 180
CYA: 280 (had to combine 3 parts tap water and one part pool water to estimate)

Thanks in advance for any advice. Posting via Tapatalk so not sure my signature will post - will add if needed.

 

[ndnile]

Sometimes photos help to document progress. Will post another after bead blasting of waterline tile.

 

[duraleigh]

Since the lowest the K-2006 measures for pH is 7.0, you could be lower than that.

I would bring pH up to 7.4 using PoolMath to calculate the dosage and 20 Mule Team Borax to affect the change.

I would also disregard any tests by anyone else and use your K-2006 as your reference.

What is the pH, CH and TA of your Fill water?

I know it's off your topic but your pump is much too large for your filter and pool. I would never run that pump at full power.

 

[ndnile]

Looks like the pH of my pool water is off scale <7.0 and my fill water is off scale >8.0 (see photos). I would love to have a TFTestkit, but shipping to 96734 in Hawaii is cost prohibitive. Any other sources?

Fill water - pH: 8.0+, TA: 55, CH: 40

Thanks for the caution on the potential oversized Pentair Intelliflo VS pump. Pump manifold is 2" but suction & return lines are 1 1/2" flex (old pool from 1980). I usually filter at 1800 rpm for 10 hrs a day with filter pressure of 9 psi. Spa runs at 2900 rpm, and while I don't know the flow rates, any higher creates too much back pressure on the air intake for the "bubble" action.

Any other advice or preventative maintenance steps prior to my refill is very much appreciated - I'm very new to pool ownership and welcome any tips.

 

[duraleigh]

try poolsupplyworld.com for TF-100 test kit. I am pretty sure they have flat rate shipping for the kit.

I usually filter at 1800 rpm for 10 hrs a day with filter pressure of 9 psi.

That sounds just about right.

Since you are draining, your high pH fill water may cause the pool pH to be too high. Lower it with muriatic acid if that's the case.

 

[ndnile]

The draining of the pool and bead blasting went well, and I'm in the final stages of sweeping up dust and debris before filling the pool. Could I ask for some advice on the recommended levels and order of adding chemicals?

Pool was re-tiled about 10 years ago with one-inch blue tile
Fill water - pH: 8.0+, TA: 55, CH: 40, water temp 83 degrees F

My assumption is that once I know the volume (to be read from the water meter during filling), I can then go to PoolMath and calculate additives (using 12.5% bleach) based on the recommended levels for plaster (is this correct since I have a tiled pool?). My initial target values are:

FC: 4.0
pH: 7.5
TA: 80?
CH: 250?
CYA: 30 initially, but may let it come up to 50-70 eventually if sunny Hawaii requires

Do these levels seem ok for a tiled pool in Hawaii? I'd like to keep calcium silicate scaling tendencies to a minimum as that is what we just removed. Is there a specific need to bring the CH up to any certain minimum level (tile grout?), or can I keep it low to help reduce calcium silicate scaling tendencies via a slightly negative CSI?

Thanks for your comments and help. I'm getting excited to have my levels in order for the first time ever!

 

[ndnile]

Pool is now 3/4 filled and I'm putting together my chemical addition procedure. Having read dozens of posts last night in addition to pool school again, here's my draft:

Pool refill startup procedure

1. Fill pool and verify volume from city water meter.
2. Backwash filter once level reaches skimmer and then put into filter 24/7 mode.
3. After circulating for two hours, test levels to establish a baseline.
4. Use PoolMath to calculate chemical additives that bring levels to the initial targets shown in the table below.
5. Add chemicals in order listed using 2/3 of the calculated requirement to avoid overshooting (except for chlorine – add the full amount). Respect the circulation times required before retesting.
6. Hang sock of granular CYA in front of return line to dissolve over the course of a week (do not backwash or test CYA level for one week).
7. Brush and vacuum as needed.
8. Test, adjust, and monitor.



This is based on my fill water and pool as described in earlier posts, and I'm still hesitant to add so much CH due to my scaling history. Please critique and offer feedback when time permits - I'll be starting in a few hours. Many many thanks to this forum and to those who have documented the refilling process before.

 

[ndnile]

Startup after refill went well. Chemistry balanced quickly using the procedure above. I placed my sock of CYA inside a PoolSkim and found that it completely dissolved within 24 hours, though I'm still waiting a week to test the level. I anticipate traveling and the use of pucks for two weeks, so I'm keeping CYA target at 30 for now.

Remaining concerns / questions are below:

1. CH is still at 40ppm. What level should I raise it to, given my history of calcium silicate scale? I don't want to overshoot without some advice from you guys.
2. Am I correct in using "plaster" in PoolMath when I have a tiled pool?
3. Does anyone have specific advice for the Hawaii (Oahu) climate that would affect my target levels?

Thanks for any advice.

Blake