Did the PB size my SWG correctly?

[mjlong1999]

My new pool can't seem to maintain FC above 0.5. Current readings are:
FC 0.3
PH 7.8
TA 80
CYA 70
Salt 3200
Phosphates 100

Pool info: 15'x40' 16k gal, IG, Black Plaster, Water Fall, All Pentiar equipment, DE FNSP48, Intelliflo VS, SWG IC20, Kreepy Krauly Legend, SGM Spray Deck, Built - 6/2014

I've been to the pool store and had them confirm my readings and they gave me some "clor-brite" to bring the FC up to about a 10 then over the course of a three days it dropped down back to a 1 then back to 0.3 after 3 more days. The pump and SWG are running 18-24 hours a day and the SWG is set to 100%. I contacted the PB and he sent the warranty tech out from Pentiar and they did the "bucket test" on the SWG and it tested okay. The tech said he would have done a larger unit.

Some other info:
Pool temp is currently 90+ deg F. The pool is in full sun most of the day. I haven't had any algae yet but the pool has felt slimy at times. Slimy goes away if i add clor-brite.

Both the PB and the tech that installed the SWG said I really should be running it about 10 hours a day and it should keep up with out an issue.

Any help here would be greatly appreciated.

 

[JasonLion]

Welcome to TFP!

An IC20 on a 16,000 gallon pool is smaller than I would have gone, but should work if you have enough pump run time. If you have any problems it should only be on the very hottest days of the year or if you want to shorten your pump run time.

I am very worried about all of that chlor-brite you used. That is dichlor, which raises the CYA level very very quickly and rapidly leads to problems.

The first thing to do is to SLAM the pool and get everything in balance manually, only then can you see if the SWG can take over. See the SLAM instructions in the How To section of Pool School.

 

[YippeeSkippy]

I see no mention of your own quality test kit here. Are you testing yourself or depending on the pool store's questionable results? I suspect your results are from a pool store because most of the home kits don't test for "phosphates" (which are a moot point as long as your CL is appropriate which keeps the algae away).

If you ever feel your CL isn't high enough and your SWG isn't keeping up, go ahead and augment it with immediate acting liquid chlorine (aka bleach) so that you have a constant chlorine presence while you're figuring out what's going on. Nothing worse than reading about a brand new pool turning green while you're learning the ropes. And most importantly, test-test-test!!

 

[Kiss4aFrog]

Having a FAS-DPD test kit is helpful if not necessary to get control of your pool. You can use a pool store for testing but for the money you spend driving your sample back and forth and the inconsistent results in the end your own kit and testing is the cheaper and better way to go. The TF-100 http://tftestkits.net/splash-page.html is recommended as it's a better value but the other kit is a K-2006 http://www.amazon.com/Taylor-Complete-FAS-DPD-Water-K-2006/dp/B0002IXIIG

 

[mjlong1999]

Thanks for the feedback so far. My test kits are the Pentair Rainbow (78HR) and I've used the HTH 6-way test strips along with the pool store results.

The pool store said the dichlor / clor-brite was just pure chlorine. I was just on the phone with the PB and the warranty guy representing Pentair and he was telling me i should be adding a cup (8oz) of dichlor every week during the hot months. I let them know i wasn't happy with that answer and the PB said again that i really should only need to run the SWG for about 10-12 hours a day.

The pool has been running for ~48 hours now non stop and I'm at 0.3 for FC.

I'll take the advice on SLAMing now.

In the mean time I told the PB if the difference was only $82 for the IC40 then they should just "upgrade" it now because the IC20 is clearly not cutting it.

 

[mjlong1999]

Welcome to TFP!

An IC20 on a 16,000 gallon pool is smaller than I would have gone, but should work if you have enough pump run time. If you have any problems it should only be on the very hottest days of the year or if you want to shorten your pump run time.

I am very worried about all of that chlor-brite you used. That is dichlor, which raises the CYA level very very quickly and rapidly leads to problems.

The first thing to do is to SLAM the pool and get everything in balance manually, only then can you see if the SWG can take over. See the SLAM instructions in the How To section of Pool School.

I wanted to check on this and make sure i was telling you wht was used. the "Chlor Brite" says Step 2, Quick-Dissolving Concentrated Chlorinating Granular. "Use for Shocking or Everyday Clorination" Active Ingredient: Sodium dichloro-s-triazinetrione dihydrate

My quick question back is will this raise my CYA level?

 

[svenpup]

Yes, that is dichlor which raises CYA. You can use the "effects of adding chemicals" section of pool math to determine how much.

 

[Kiss4aFrog]

I'm pretty sure it does. If it's Leslie's beside the "info" you posted above it does say "UV ray inhibitor" which in my book says CYA. http://www.lesliespool.com/leslies-...-multipack-bags/chlor-brite-granular-bags.htm

This was a cut and past for 3" tablets.
Trichlor adds 0.6 ppm CYA/ppm FC, and dichlor adds 0.9 ppm CYA/ppm FC

 

[mjlong1999]

Thanks for the input and I'll for sure stop adding the Chlor-Brite. The PB has agreed with me and they are going to install the IC40 tomorrow. That should help get FC up in a more reasonable amount of pump run time.

 

[ping]

The IC40 will help, but you still need to go through the SLAM process to kill everything off, even though you don't see algae it is there, and only then will the SWG be able to produce enough chlorine to stay ahead of the algae. Right now the pool has what is called nascent algae.