Preparing for Opening a Pool After 3-Year Hibernation


Silver Supporter
Mar 8, 2017
Coopersburg, PA

I'm a new homeowner inheriting an inground vinyl pool (18' x 35'). I have a Pentair FNS Plus 60 DE Filter, a Pentair Challenger High Performance 1 hp Pump and Hayward skimmer controls/valves. Also, I believe I have an Olympic chlorinator.

The 18 year old mesh Loop-Loc cover is shot and has been on this pool for what will be three years this coming autumn. I had a pool inspection done before buying the home and the company that did the inspection was the same company that winterized/closed the pool the last time it was closed. The vinyl liner had been replaced just before the pool was closed for the last time. Vinyl liner was inspected and is in good condition with water at operational level (so, apparently no leaks). The pump was tested and is working as of the inspection in February. The pool inspector says the filter grid needs replacing.

I have ordered the TF-100 Test Kit with magnetic stirrer. I am putting together my to do list in order to open and SLAM this pool in the next few weeks. Here are a few specific questions:

1. With all the "yuck" in the pool after sitting dormant for two to three years, should I take off the cover and just work on getting as much of the "solids" out as I can?

2. Any advice on figuring out how my vacuum system works? I can't find a dedicated vacuum line so does that mean I plug my vacuum head and hose into a skimmer?

3. Should I replace the DE filter grid prior to opening, cleaning and SLAMming or should I just make due with what's in the filter for now and replace the grid once the pool is closer to clean?

4. What chemical list do I need to buy and have on hand for the SLAM process?

5. How should I test or check the equipment to tell whether or not it needs other servicing in order to be brought up to operational condition?

Thanks for your help and advice!

18' x 36' inground vinyl liner pool | Pentair FNS Plus 60 DE Filter | Pentair Challenger High Performance 1 hp Pump | Hayward Skimmer Controls/Valves | Olympic Chlorinator | 2 Skimmers | ???? gallons | Loop-Loc Dura Mesh Safety Cover
Last edited:

Texas Splash

Mod Squad
TFP Expert
LifeTime Supporter
I have ordered the TF-100 Test Kit with magnetic stirrer.
I wish every new thread started this way. :) Makes things sooooo much easier. Now for your questions:
1 - Yes
2 - Probably so. If you see no dedicated port, or only have one pump (not variable speed), you will probably manually vacuum from the skimmer
3 - I would inspect now because if the grids are torn, you won't be able to filter (SLAM) properly. However if you have a multiport valve (not plunger), you can filter to waste in the beginning to get some of the "muck" out of the pool.
4 - Muriatic acid to lower pH to 7.2 (if it's high) and a good amount of regular (plain) bleach. Several gallons for sure. Oh, and some granular stabilizer to ensure the CYA is at a minimum of 30.
5 - We already discussed the grids. The pump will tell you quickly upon start-up. Watch the pump basket to see if water fills-up to the clear lid and stays there. Watch the system for air bubbles and/or leaks. Otherwise, you should be in fairly good shape.

Hope that helps! :)

Before you add stabilizer (CYA) to start the SLAM, check with us first. If your water has been sitting there for 3 years, we may want to rule-out ammonia before you add stabilizer.