Installed SWG this weekend

Jump to latest Follow Reply
B

bluenoise

0
LifeTime Supporter
Jul 25, 2007
182
Alamo, CA
After successfully getting my CYA down to the ~80 range, I got all my other chemicals into balance. I used over 15,000 gallons of water getting that CYA down! I spent yesterday afternoon installing my new SWG. I added the salt in the morning to let it dissolve. Everything went quite smoothly and I've been allowing the pump to run all night. I tested the water this morning and got these results:

Water is crystal clear
FC: 0 (Man, where did it go? It was at 10 yesterday morning!)
CC: (Didn't test, but it was at 0.5 Saturday morning)
Ph: 7.5
TA: 90
CH: 200
CYA: 80
Salt: 3560 (Apparently, my pool isn't really a full 20,000 gallons as I overshot my target of 3200)

So, it looks like I need to replace a little more water to get the salt down. It also appears I should add some calcium in to bring the CH up a bit. And, obviously, I better pour in some bleach.

I haven't turned on the SWG, yet, as the manufacturer wanted me to run the pump for 24 hours before I do. I will be firing it up this evening. Should I reduce the salt level before turning on the SWG or will it be OK with a little too much salt?

Based on my numbers, what do you recommend I do? What are my targets?

Thanks!
 
Bluenoise, you probably have figured you have something consuming your chlorine, I would suggest doing the CC test and going from there. That and the sun are the only reason for it disappearing, and your CYA level looks great. I run my Aquarite on 40% and it keeps the levels around 4PPM Chlorine. What is your aquarite saying for salt levels, have you turned it on yet? I think that 3600 is a tad high, so I would just do some backwashing and then refill. Checking it two hours after you do the refill. I think all your other #'s look great.

Rik
 
Thanks, Rik. I'm guessing the FC was killed by the sun on Saturday. I tested in the morning and read 10, but then it was 103 degrees in the shade with full sun on my pool. I'll check CC, though, just to see. I still have the sample from the pool. I've already just added the bleach to get some chlorine in there again.

I haven't turned on the cell as I was afraid the salt being over the recommended range by a wide margin might cause problems.

I'm draining and refilling for an hour or so before I head to work in an effort to drop that salt level.

Do I need to raise my CH? I suspect it's going to go down a bit more with the additional water replacing I'm going.

BTW: In spite of it being 103 degrees on Saturday, my pool temperature is now down to 78 because the air never got above 66 degrees yesterday and there was no sun (high fog). Sunday was nearly 40 degrees cooler than Saturday! That's pretty weird around here. It's only 61 right now, too (8:45 AM).


ETA: I just tested the CC at 0.5 ppm.
 
Blue, the numbers you posted the other day are good,(excepting the cl that disappeared on you :shock: ) you are slightly scaling - which is what most manufacturers want for the cells - and the heater folks agree with them.

I would have turned the SWCG on before dumping water and refilling, just to see if the unit 'thought' there was too much salt in the water, but what's done is done 8) - you will want to do a full retest of the water again as the partial drain and refill may have changed the chemistry.

You probably had some salt in the water before you added (I'm assuming) ~530 lbs , your pool may actually be 20,000 gal However, if your water had no salt and your salt test can be believed - your pool is 17,977.52809 gallons - you added an extra ~50 lbs of salt and as such each 30 lbs of salt should increase the salt ppm by ~200. (yes, I do realize that the numbers I give don't quite add up, but I'm generalizing and doing some rounding for not only my ease, but that of anyone who reads this :roll: ) The point here is that you can use the amount of salt added to a pool and the subsequent rise in salinity to get a good idea as to the actual gallonage of the pool which will be useful when adjusting any chem level. As you've already learned, always add less of a chemical than you think you need when adjusting the water, it's usually easier and cheeper to add in 2 or more doses than to have to dump and replace some water or add another chemical to counteract any overage. :goodjob:
 
This evening, I would shock the pool with bleach....don't ask your SWG to do it...it's too much of a load.

Losing 10ppm with a CYA of 80 indicates to me you have too many organics (algae, etc. doesn't have to be visible) in your pool. Clear those out with bleach and then let your SWG take over for maintenance in the 2-4 range.
 
waste said:
Blue, the numbers you posted the other day are good,(excepting the cl that disappeared on you :shock: ) you are slightly scaling - which is what most manufacturers want for the cells - and the heater folks agree with them.

I would have turned the SWCG on before dumping water and refilling, just to see if the unit 'thought' there was too much salt in the water, but what's done is done 8) - you will want to do a full retest of the water again as the partial drain and refill may have changed the chemistry.

You probably had some salt in the water before you added (I'm assuming) ~530 lbs , your pool may actually be 20,000 gal However, if your water had no salt and your salt test can be believed - your pool is 17,977.52809 gallons - you added an extra ~50 lbs of salt and as such each 30 lbs of salt should increase the salt ppm by ~200. (yes, I do realize that the numbers I give don't quite add up, but I'm generalizing and doing some rounding for not only my ease, but that of anyone who reads this :roll: ) The point here is that you can use the amount of salt added to a pool and the subsequent rise in salinity to get a good idea as to the actual gallonage of the pool which will be useful when adjusting any chem level. As you've already learned, always add less of a chemical than you think you need when adjusting the water, it's usually easier and cheeper to add in 2 or more doses than to have to dump and replace some water or add another chemical to counteract any overage. :goodjob:
Click to expand...

Thank you for the good info. I tested the salt content before I went and bought salt. It said I had about 350 ppm (I think, anyway. I have to see what I wrote down after I tested as I may be remembering incorrectly with all these numbers bouncing around in my head). I bought 550 pounds, but only put in 400 thinking I'd rather be too low than too high. I ended up too high anyway, of course. I should do a little math to see how many gallons I actually have for future needs.

I added 182 oz. of bleach this morning before heading in to work.

Should I raise the CH?
 
I would not worry too much about a salt level of 3600 ppm. It just means your cell won't have to work as hard to produce chlorine and it will actually prolong cell life. As long as you don't get a high salt condition you should be fine.
 
Here are my numbers from this morning:

Perfectly clear

TA: 85
Ph: 7.5
FC: 10
CC: 0.5
CH: 180
CYA: 80
Water Temperature: 75
Salt: 3100 (but the SWG says it's 2900)
CSI: -0.6

As I have a plaster pool, it seems to me my CSI is way too low. Also, my CH is quite low. So, should I add calcium? Should I raise my Ph? What should I do about the low CSI?

Thanks!
 
Add calcium soon or raise PH to 7.7 or so until you can work on the calcium. Unless the plaster is new (less than two months old), then don't worry too much about the calcium as it will come up naturally.
 
What level of CH should I target? the plaster in my pool is very old and is even showing a bit of the gunite in some areas.

How accurate is the salt level reading on the control box? It's showing 2900 while the test strip showed about 3100.
 

Enjoying this content?

Support TFP with a donation.

Give Support
This morning's numbers:

FC: 20
CC: 0
Ph: 7.6-7.7 (somewhere in between)
TA: 90
CH: 180
CYA: 85
Salt: 3200 (display shows 2800)

Well, the SWG appears to be working. My free chlorine doubled since yesterday morning and my CC went to zero, so I'm guessing it "shocked" the little CC I had. I just reduced the SWG's percentage from 75% to 45% to see how that affects things.

I will add the calcium today and test again tomorrow to see how it affected it. I will carefully measure everything to get a more accurate value of my pool's water volume based on the changes in CH.
 
Two things seem to make working with a SWG easier. Keep some bleach on hand for those "bad" days (excessive rain, wind, pool usage, "accidents") - as was said before, you can prevent a lot of problems by hitting the pool with a gallon or 2 of bleach when your FC gets hit and the SWG is going to take some time to catch up.

Second, make adjustments early! If your FC seems low, don't hesitate to notch your SWG up a bit. And the other way around. Again, it takes your SWG time to build up. A little excess FC doesn't seem to be noticed by swimmers. I think of my SWG as operating within a range of settings (maybe 35 to 50% during peak summer use) and don't hesitate to work the dial as needed.
 
I reduced the SWG's run percentage from 75% to 45% and my FC was 5 this morning (vs. 20 yesterday). Is such a drop reasonable given my CYA level of 85? As far as I can tell, I've been algae-free for a couple of weeks. There are some leaves dropping into the pool lately. Could they be sapping my FC?

I upped the SWG to 60% (split the difference) to see where that puts me.

After adding 15 pounds of "Leslie's Hardness Plus," my CH is now 290. By my calculations, my pool is actually 14,750 gallons, not 20,000 as I had calculated by dimensional measurements a few years ago. That certainly explains how I over-salted it!

What's amazing to me, too, is that I must have replaced virtually all of the water when I was trying to reduce my CYA to a decent level.
 
FC dropping from 20 to 5 in one day with CYA of 85 is unusual. I would expect it to drop by one third or less, so to something like 12-15. If several people were swimming that could do it, otherwise it suggests something growing in the water or some chemical interaction.
 
I've been giving this more thought. Please tell me if this is a plausible explanation for the FC drop. When I collected the water sample yesterday, I took it from about 18" deep at a point farthest from all the return jets. The pump and the SWG were running. It was then I got the 20 reading. Today, I collected from the same location in the pool, but it was before the equipment turned on. I got the reading of 5. Though that location in the pool is away from the return jets, it is still in a place where the strongest jet causes a bit of turbulence (it's directly opposite that jet). Could it be the return water has a much-higher FC concentration and I happened to collect mostly that?

I will test again tonight an hour or more after the equipment is off and again in the morning before it turns on. That should tell me if anything is killing my FC, right? The sun stops shining on my pool around 4:30-5:00 PM this time of year. My equipment runs from 7:00 AM to 8:00 PM.
 
Testing the water when it is not throughly mixed can result in strange readings. Generally if the pump has been running for half an hour or more the water will be fairly well mixed. After the pump has been off for several hours and there has been sunlight on the pool the chlorine levels can vary from place to place in the pool fairly dramatically.
 
I tested last night after dark and got these numbers:

FC: 6
CC: 0

I tested again this morning before the sun hit the pool and got these numbers:

FC: 5.5
CC: 0.5

I also noticed a touch of greenish dust on the walls (algae?!) so I brushed it off. If it's there again this evening, I'll do a shock with some bleach tomorrow.

I think I know now why my chlorine dropped from 20 to 5 in one day: It wasn't at 20. I had to have forgotten to divide the number of drops by two with the FAS/DPD test. Surely, I'd remember adding 40 drops to the solution! :oops:

It looks like the current setting on the Aquarite is about right for maintaining my chlorine level, so I'll leave it alone for another couple of days while I continue testing. I suspect my filter still has some algae in it. It needs cleaning anyway, so I'm going to do that tomorrow morning and then shock the pool.
 
I'm still trying to find the right setting on my SWG so that it maintains FC at a good level. Even at 20%, my pool's FC climbed a bit during the day yesterday. Monday night, it was 7.0. Last night, it was 8.5. So, this morning, I dropped it down to 15%. While I realize this would be great for preserving my cell's life, I'm wondering if it's actually cycling at all. I have it in its normal run mode, not "superchlorinate" mode. I run the filter pump for about 13 hours per day.

Does this seem right? My CYA is around 80 or so. I'm trying to get it to drop gracefully. I could leave it off for a day or so to let it drop quickly, but I don't want it to drop below 3 or so while I'm not watching it.
 

Enjoying this content?

Support TFP with a donation.

Give Support
You must log in or register to reply here.
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.
Top Bottom
Back
Jump to latest Follow Reply