SWG with and without solar cover. The fine tuning will drive me nuts.

[kul]

Hi friends, is there any issue with running my cell at 100%? I have been running it for 6 hours at 100% which is keeping up with the chlorine demand, but is the cell going to have issues running long term at full capacity?

 

[Donldson]

Most, if not all cells are like microwaves: when you set a % it just cycles on and off. So even if you set it to 50% it's still running at 100% for half the time and off the other half of the time.

It shouldn't be an issue to run it this way.

 

[Griswald]

The real question is why is your chlorine demand do high?

 

[kul]

The real question is why is your chlorine demand do high?

Hmmmm. This generates 4ppm of chlorine a day according to poolmath so with weather sunny and in upper 70s/low 80s and water in the 70s seems pretty normal to me. Seems my pool uses 2-4 chlorine each day. It does have a solar cover, but there are exposed areas my guesstimate is 25% is exposed.

How much chlorine does your pool use a day?

 

[Jimrahbe]

Kul,

While it won't hurt the cell, it just does make a lot of sense to me to only run the pump 6 hours a day.. The chlorine you make in those 6 hours has to last until the pump comes back on 18 hours later...

It makes sense to not run the pump, when your electrical rate is high, but I doubt the are high for 18 hours a day.

Running a VS pump at a low RPM uses almost no electrical power.. I run my IntelliFlo 24/7, mostly at 1200 RPM for less than $20 bucks a month.. I like making a little chlorine all the time, and skimming all the time.

Just curious.. what made you select the 6 hour run time?

Thanks,

Jim R.

 

[Newdude]

seems pretty normal to me

FC loss doesn't know how you added chlorine. So if previous seasons were similar, you're good to go. But if 1 to 2 daily loss turned into 2 to 4 this year, then somethings up.

 

[kul]

Just curious.. what made you select the 6 hour run time?

Prior to SWG I used to run my pump 6 hours a day during the warm season and 4 hours during the cold season. I was using liquid chlorine during that time. In previous years I had a solar cover both on the pool and spa area so coverage was around 95%.

With the SWG during the cooler time I ran my pump for 4 hours and had the SWG running at about 60% for 2 hours each day. Sometimes I’d decrease it or increase it depending on the chlorine level.

Recently I added my solar cover for this year which is on the pool part only (not spa) and is smaller so not as fully covered as last year -I’d say 75% of water surface area is covered. I recently added CYA because it was low and my FC was burning off faster (we had heated the pool for a few days to 90 and left it uncovered during use). I then increased my pump run time to 8 hours (6am-2pm) and have the SWG running 6 hours (7am-1pm). This seems to be keeping up.

But if 1 to 2 daily loss turned into 2 to 4 this year, then somethings up.

I was looking at my pool math logs and I can’t tell if what I’m seeing is off. With the fully covered pool I used to lose 1-2. Now that I have more area exposed it seems to be 2-4.

 

[Newdude]

With the fully covered pool I used to lose 1-2. Now that I have more area exposed it seems to be 2-4.

Could be easily explained with less coverage. Could also be easily proved by Overnight Chlorine Loss Test

I know you don't like to leave things to chance.

 

[kul]

@Newdude I had a feeling an OCLT was about to be in my plans. Will report back tmr.

 

[Newdude]

It's mostly sus because of how early it is in the season. If it was July, it'd be more plausible.

 

[pjt]

Are you trying to take advantage of TOU rates? You might be able to operate 24/7 for negligible cost. However, California may have very high electric rates. What are you paying per kWh?

 

[kul]

Are you trying to take advantage of TOU rates? You might be able to operate 24/7 for negligible cost. However, California may have very high electric rates. What are you paying per kWh?

20 cents/ kWh up to 1000 and there’s tiered pricing after that for next 1000.

I was trying to only run the pump as needed. LADWP recommends running pool pumps 4 hours in winter and 6 hours during summer and that has worked out fine for my needs with liquid chlorine. Once changing to SWG I increased the run time to 8 hours since the weather got warmer/sunnier because I noticed I was no longer producing enough chlorine to keep up.

I have to run it at 2000rpms to get the spa spillover to work properly. Since I have a solar cover the skimming is less effective so my main reason for running the pump as many hours as I have been is so that my chlorine levels stay in range. We had recently heated the pool and left it uncovered and I saw how much chlorine that used up so figured upping my SWG run time and % would help.

My pool is clear and I don’t notice anything that would indicate algae but am going to do an OCLT tonight so will know more tomorrow.

I’m new to the SWG so am open to making adjustments once I see if the OCLT is ok.

 

[jmastron]

I've been running my generic Calimar SWCG at 100% for 3 years now -- not continuously of course! I control the generation time with a cheap WiFi plug, so I can easily adjust since I test inside, a good distance from the pool, and don't want to go out to touch the dial. As mentioned, the SWCG doesn't care if it's run for 100% for 6 hours, 50% for 12 hours, 25% for 24 hours; there shouldn't be any real difference in wear/lifetime.

In addition, if you're using a timer 100% avoids an issue with some units with what seem like ridiculously long cycle times like 180 minutes (so setting the unit to 50% and then using a timer for 4 hours might actually result in 3 hours on, 1 off, or 75%). But otherwise it's all up to whatever fits best into

I echo the questions about FC usage and generation. If you're data oriented, you could do 3 experiments:

1) Overnight chlorine loss (SWCG off), tells you if anything besides the sun is using FC.
2) Overnight chlorine gain (SWCG on 100%), tells you what the actual generation rate is. Some brands/models have been reported to be way less than advertised.
3) Daytime chlorine loss (SWCG off), to match up to how many hours to run.
3a) If you have a solar cover and leave it on some days like I do, a second daytime chlorine loss with cover on (SWCG off) can help adjust as needed.

 

[kul]

2) Overnight chlorine gain (SWCG on 100%), tells you what the actual generation rate is. Some brands/models have been reported to be way less than advertised.

Thanks for the suggestions. I basically did this today and my SWG seems to be producing chlorine at the amount calculated by pool math so I am in the clear there.

My SWG runs 7a-1p. I will check it tonight around 6:30/7 when the pool is no longer in the sun and will check again tomorrow morning before 7am (before the SWG turns on).

My solar cover is always on unless we are going to be swimming. On those days I put it back on after we are done for the day. If we plan to swim the whole weekend I might leave it off an extra day.

 

[Rancho Cost-a-Lotta]

FWIW, my SWG is set for about 2.5 ppm FC per day with CYA at 70 ppm.

I'm curious why you need to run your spillover for the entire runtime. If you're concerned about properly chlorinating the spa, just set a program that allows spillover for a couple hours. If I recall correctly, you do not have automation? If so, you could just run spa mode for about 30 minutes. Cutting down your RPM significantly reduces energy use. A reduction of about 50% results in 7 to 8 times less energy use.

 

[kul]

I'm curious why you need to run your spillover for the entire runtime. If you're concerned about properly chlorinating the spa, just set a program that allows spillover for a couple hours. If I recall correctly, you do not have automation? If so, you could just run spa mode for about 30 minutes.

I think what I have learned so far is that I need to monitor my FC usage for a few days to help me figure out how best to set my SWG % and hours. I don’t have a handle on how much is actually being used, just my guesses based on the testing I do a few times a week. I’m a bit frustrated because when I was using liquid chlorine I had a schedule that worked well for me and now I feel like the SWG is in charge and we are not communicating well.

I wanted to “set it and forget it” which is why I have the spa spillover always on to some degree. I do not have automation.

 

[kul]

@Rancho Cost-a-Lotta do you run your pump and SWG 24/7? Are you using a solar cover right now?

 

[Rancho Cost-a-Lotta]

I'm not using a solar cover now, but I plan to install it soon. For me, a solar cover allows me to run at a lower speed because I'm less concerned about skimming. I also find that my FC loss decreases by nearly half.

This is the first year I've been experimenting with running 24/7. I have solar power and I'm on a tiered plan. Between 4:00 p.m. and 9:00 p.m. my current electric rates are around 60 cents per KWH. The slowest I can run my pump is around 1400 RPM before the SWG and/or heater shut down. For my pump that's about 200 watts. So, just to run it between 4:00 p.m. and 9:00 p.m. costs me about $18 per month. I just need to decide if it's worth the extra cost. I do notice that my pool is always skimmed, and seems much cleaner.

 

[Newdude]

I’m a bit frustrated because when I was using liquid chlorine I had a schedule that worked well for me and now I feel like the SWG is in charge and we are not communicating well.

You just need to play the game a little different. The pool will lose FC like it always did and the SWG will add LC like you always did.

You test the FC after to decide if it was miking too little, or it's good to ride as is. A little high isn't worth turning it down, just to have to turn it back up in 2 or 3 days. That's where you go nuts micromanaging it.

This it the tricky time of year as daily demand bumps up a couple of times and it might even be on consecutive weeks, catching you off guard. After that, you'll be at a constant level for the peak season, then spend the back half of the season over producing everytime the daily loss lowers a little.

 

[mas985]

Hi friends, is there any issue with running my cell at 100%?

You may find that the cell will develop scale much faster when running at 100% even when accounting for run time. This is because any scale that may have collected while it was on does not have the opportunity to redissolve back into solution when off. It just keeps collecting the scale. So it may be harder to clean off as well.