Opening After 3 Year Hibernation

mcolflesh · May 23, 2017

Hello,

I began opening my pool for the first time after a 3 year hibernation. We purchased a home this spring including an 18' x 36' vinyl liner pool (~26,700 gallons), which has been closed for the past two winters. So, I removed the cover this past weekend; unplugged both skimmers and inlets, removed the Gizzmos from the skimmers, replaced the drain plugs in the pump, filter basket and chlorinator. I began with some surface and deep skimming to remove solids.

I did some experimenting with the filter to begin understanding how the multi-valve worked along with troubleshooting various aspects of the DE filter. After doing a tear down of the DE filter (Pentair FNS Plus 60) I learned I needed to replace the manifold (original was cracked) and install a bulkhead O-Ring (no O-Ring in place when disassembled). I had purchased filter grid replacements by Unicel since the pool inspector was the same one who winterized it almost 3 years ago. He indicated some of the filter grids needed replacing. So, reassembled the filter with the cracked manifold, missing O-Ring and put back a few of the less damaged grids. I fired up the filter and added the recommended amount of DE in order to just try out the filter. The pressure at startup was ~15psi and within an hour was at 27psi so I felt nervous and shut the whole thing down for now.

Waiting on my manifold and O-Ring. These arrive tomorrow and I plan to backwash and rinse the filter, install the new manifold, replace any other cracked filter grids, install the bulkhead O-Ring, and recharge with DE, then keep the pump and filter running for the SLAM.

I have the TF-100 test kit and am planning to begin a SLAM this Memorial Day Weekend. After watching several videos, here is my strategy. Please comment and criticize - feedback is welcome:

1. Get the Pump and Filter up and running - IN PROCESS

2. Test, Test and Retest the water as follows:
a. Test for pH (before adding any chlorine) - looking for 7.5 - 7.8 (add soda ash to increase pH as necessary and add muriatic acid to reduce pH as necessary)
b. Test for CYA - looking for 30 - 60 ppm for non-saltwater pool (see pool calculator to add or lower CYA)
c. Test for Free Chlorine
d. Determine Shock Level (see TFP for chart of CYA - FC recommendations)

3. Start SLAM once pH and CYA levels are known

Okay, I will have follow up questions if you give me feedback so thank you in advance! Also, here are a couple of "before" photos once the cover came off.

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Texas Splash · May 23, 2017

a. Test for pH (before adding any chlorine) - looking for 7.5 - 7.8 (add soda ash to increase pH as necessary and add muriatic acid to reduce pH as necessary)
b. Test for CYA - looking for 30 - 60 ppm for non-saltwater pool (see pool calculator to add or lower CYA)
c. Test for Free Chlorine
d. Determine Shock Level (see TFP for chart of CYA - FC recommendations)

Actually, a couple modifications to your strategy:
a. Lower pH to about 7.2 before starting the SLAM
-- Before adding stabilizer, add only enough bleach to reach an FC of 10. Make sure it gets there, then re-test in 10 minutes. If it remained close to 10, no less than 5, than go to next step (b) below. Otherwise, repeat adding bleach and re-testing every 10 minutes until the bleach holds.
b. When you get ready to add stabilizer, only go for 30. You'll use less bleach that way,
c. Always - frequently at first.
d. If you get to CYA of 30, the SLAM FC level will be 12. If your CYA is closer to 40, the SLAM level is 16.

That filter will clog like crazy. You can vacuum some to waste, but water will go fast. You can run on recirculate for times when you're away from home or asleep if you're concerned about psi increase, but eventually it will need to filter 24/7. Just hang in there. That's quite a pond you're converting.

Hope that helps.

JVTrain · May 23, 2017

Sounds like a pretty good plan of attack. A couple of notes...

Before starting to elevate FC to shock levels for SLAM, lower the pH to 7.2. When the FC is above 10 ppm, the pH test is invalid and will usually read very high. You cannot directly measure pH when FC is this high so starting with a low pH is better, since pH tends to rise over time more often than not in pools.

Add enough CYA to the pool to only get to 30 ppm when starting the SLAM. Lower CYA = lower required shock level for SLAM. Be sure to dissolve the CYA in a sock placed in a skimmer basket or hung in front of a return.

The more crud you can get off the bottom by blindly raking with a pool leaf net, the less chlorine you'll need to get things going and throughout SLAM.

Looking forward to seeing this beast transform!

spinPHD · May 23, 2017

The two post have you covered, but be sure to post your test results one you take them. Also, keep usupdated with pics. You can do this

mcolflesh · May 24, 2017

Tore down filter again after backwashing and rinsing. Replaced manifold and remaining broken grids. Tried to install replacement O-Ring for bulkhead only to find it's 1/4" too large - why is this? I looked up the correct part number in the Pentair FNS manual and ordered Torx replacement O-Ring. Anyway, finished reassembling filter and recharged with DE.

Took following water tests before firing up filter so the water had been sitting for three days without any filtration:

Chlorine - 0
pH - <6.8
Chlorine Drop Test - 0
CH-25ppm
TA - 0 (after adding 5 drops of R-0008 the solution never turned green - only red)
CYA - between 90 and 100

Ran the filter for 30-40 minutes and the clean filter ran at 13psi. Within 30-40 minutes it was at 30psi after brushed and deep skimming. Backwashed, rinsed and recharged with DE. Ran the filter for 10 minutes and then turned it to recirculate for the night.

So, what now?

Texas Splash · May 24, 2017

The #1 concern for me is still that elevated CYA. A CYA of 80 requires an FC SLAM level of 31. That's a lot of bleach and R-0871 drops. If I were you, I'd try to lower that CYA some more before trying to adjust anything else.

mcolflesh · May 31, 2017

UPDATE: Initial goal of reducing CYA - drained and refilled 50%-60% of the pool (see attached photos). Drained to just below the pool light and refilled with well water. New test results are as follows.

CYA: 30-50 (overcast conditions - will retest in better lighting)
FC: 0
pH: 6.8 (please see photo of pH test results and agree or disagree with this reading)
CH: 75
TA: 50 (5 drops of R-0009 until mixture remained red after mixing; 3 drops until it began to turn red but turned clear as it was mixed)

So, what are my next steps before SLAMming?
-Retest CYA in better lighting to ensure accurate reading (I also ordered the 50ppm CYA testing solution from TF Test Kits to "calibrate" my eyes to the CYA test as it seems so subjective)
-Play with pH? Should I bring the pH up closer to 7.2 before SLAMming?
-Any other advice?

Thanks in advance!

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