All set - now just waiting for SWCG to arrive!

Mar 25, 2015
17
New Zealand
Pool Size
50000
Surface
Plaster
Chlorine
Salt Water Generator
Am mostly set with the chemistry in our 50,000L plaster pool to convert from liquid chlorine to SWCG.

FC 5, TA 70, CYA 63, CH 290, salt 3499, pH 7.7. Am adding boric acid this weekend, aiming for 40ppm (bit worried about killing bees tho - not that I've seen any come to drink).

I also plan to bring the CYA up to 70 over the next few days, and the CH up to around 350.

I have a reciprocating saw, pvc primer and cement ready and waiting. The smart plug is integrated into Home Assistant.

Now I just need the actual chlorine generator to arrive from eBay - a Laswim EC20 - and some warmer swimming weather!
 
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Hey Sultan !!! Glad you’re not in Dire Straits. (I’ll be humming it all day now, THANKS).

the CYA can’t be easily read between 10 values so we always round up. Call it a 70 now and just keep tabs on it once it deteriorates (4ish ppm a month plus a skootch from rain) and be ready to adjust it up when it actually hits 60.
 
s,

Congrats on the swg you're gonna love it! FYI you can use Pool Math to estimate settings and run time. Your output should be 1.06 lb/day. At this rate you should see 3 ppm FC addition with 70% power and 8 hr per day run time. With your VS motor you'll be able to optimize power consumption and it may be better to run at low speed with a much lower % power for longer run time. You can play around with this in the "effects of adding" section of Pool Math. Just select swg as the chemical and plug in the numbers. Be sure to set the pool volume.

I hope this is helpful.

Chris

PS the size of your pool in the signature is different than the size you describe. You may want to fix this.
 
Congrats 🎉
Until your swg is up & running follow the chlorine side of the FC/CYA Levels.
Go ahead & call that cya 70 like stated above so target 8-10 ppm fc for now.
You don’t wanna have to SLAM Process or start off your swg journey with a nascent algae bloom & wonder why your new device isn’t keeping up. Better to be safe than sorry 😁
 
Thanks all - great suggestions.

Yes, will get to adjusting my pool volume in the profile [EDIT: done]. I originally estimated it by measuring the width, depth etc (it's a kidney pool with a sloping shallow to deep end, and a cut out entry - so lots of fiddly bits). I've now adjusted that down based on the measured values (TFT-100 kit) of adding chemicals, set against the "effects of adding" in the pool math app. Not perfect, but better than nothing.

Having a VSD200 pump (speed 3, 125L/min for 12 hrs/d) and a smart plug on the chlorinator will allow for near infinite control. Probably too much - I won't be able to stop fiddling with the thing!
 
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I got some great advice early on from one of our experts to try not to "over manage" the swg. Your swg should be able to run at constant % power and run time such that the FC cycles a few ppm above target and down to target as use, daylight exposure etc cycle. This way you never get to minimum. For me, all I had to do was adjust run time a couple times per year. I was in my 3rd year of operation like this when we sold the house.

I hope this helps.

Chris
 
New EC20 SWCG is up and running!

Easy to install. Would have been quicker but I cut too long a gap, so had to add a piece of pipe back in. Also, the smart plug wouldn't pass current, so have connected to the same plug as the pump.

I've set it to 80% (it does 20g/hr at 100%), running 12 hours a day, and am testing chlorine regularly. Currently sitting at 5.5 FC, with a CyA of around 70. pH 7.6, CH 325, salt 3160ppm, TA 70, borates est. 45ppm. Water looks great.

Had our first swim of the season on the weekend - lovely!
 
Sweet job !!!! You are getting warmer there, right ? It takes some dialing in with regular testing (again, sweet job !!). But. After that you will be on the lookout for the daily losses getting more as the season ramps up. It’s never the same and it could be 2 weeks or 6. Whenever you see it not keeping up with demand it simply needs to produce more. Far too many people come back a month or two later and have it set too low, many times with algae from hitting minimum. Don’t worry about lifespan if it needs more production. The extended run times of the peak season average out with barely needing it early/late. So for now it’s up, up, up and then for the back half of the season it’s down down down.

It only knows what you tell it to do, so listen to your pool and adjust as necessary. (y)
 
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Without logging every test result here ....

After 3d of the above settings (80% X 12 hours run time), with pool cover on and no swimming, but a few leaves in the pool, FC has risen from 5.5 to the sweet spot of 7. Based on that, I've eased the SWCG down to 60% to see if it holds there.
 
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