Oversizing a new SWG system

[Backinsac1]

Hi, I would like to convert my current chlorine pool to a SWG system.

The capacity of the pool is about 18,000 gallons (maximum, it might be a bit lower). I have been using chlorine since we moved into the house 10 years ago.

After some research, I think a Pureline system from Inyopools might be best for me. I noticed that they have a 40,000 gallons system (PL7700) and a 60,000 gallons system (PL7703). The price difference between the two is $100 ($649 for the PL7700 and $749 for the PL7703). The replacement cell for the PL7700 is $399 and the replacement cell for the PL7703 is $449.

I understand that I should oversize the SWG system 1.5 to 2 times so the pump won't have to run too long and I could extend the life of the salt cell. If I go with the PL7700, I will oversize my system by 2.2 times. If I opt for the PL7703, I will oversize the system by 3.3 times.

Would there be any problems or issues if I purchase the larger capacity PL7703 system. This would ensure that the pump doesn't run very long and would increase my salt cell life greatly. Or would this be overkill and cause problems/issues. Or am I overthinking all this and just go with the PL7700 and be happy with that?

As a side note, should I be concerned about the availability of replacement cells for this system in 3-7 years? Do you think Pureline will still be around then?

All comments and suggestions are welcome. Thank you.

 

[jblizzle]

No problem going bigger. I think Marty has a 40k or 60k cell on a 6k pool lol.

No idea about the longevity of that brand. But INYO seems like a good company.

 

[Vickery]

Go big for a long time!

 

[markayash]

Related question. is it the cell that determines the output? If you bought a 40K system from inyo could you make it a 60K buy replacing the cell?
I guess my question is does the control unit just supply a set voltage?

 

[jblizzle]

Depends on the controller. The Hayward, you have to tell it what size cell is connected.

 

[Backinsac1]

I just emailed Inyo about using a higher capacity salt cell with a lower capacity controller box. I'll let you know what they say when I get their reply.

I did notice in their literature that the control unit does let you specify the salt cell (similar to the Hayward unit).

 

[homegameroom]

I have the Inyo 60,000 SWG for my ~10,000 gallon pool/spa combo. I've had zero issues with it (I've only had it for 6 months) and i love it. I have it running at about 15-20% for about 4 hours a day - so I hope it will last forever!!!

There is a selection on the menu for which cell you are using, so I would assume you can change to a larger or smaller unit AS LONG AS the sizes are all the same.

 

[Backinsac1]

Inyo just confirmed with the following email:

"Hi. Yes, you are able to interchange the different size cells using the same controller."

 

[Backinsac1]

Hi, just to follow up:

I order a 60K system (PL7703) Pureline system from Inyopools last Friday. Delivery should be next Monday.

Currently my water is at:

FC - 4.5
CC - 0.5
PH - 7.8
TA - 150
CH - 160 (wife added water from the water softener to the pool)
CYA - 45

I will add liquid chlorine as necessary to keep chlorine levels at 4-7 ppm until the SWG is online.
I will add acid to lower PH accordingly.
I may try to lower TA a bit. Do you think it is necessary right now or wait until the SWG is online?
Should I increase CH right now or wait until the SWG is online?

I am currently testing weekly with the TF-100 test kit.
I ordered 15 bags of Diamond Crystal Bright & Soft Water Softener Salt Pellets, 40 Lb. that I need to pickup from Walmart (at $4.94/bag). I can return any bags that I don't use.
I ordered a tube of AquaChek 561140A Salt Water Swimming Pool Test Strips - White from Amazon that should arrive in a couple of days.

After the salt test strips arrive, I will check the pool's current salt level.
I will double check the pool capacity (I think it is 18,000 gallons, but I will recalculate to be more accurate).
After checking the pool's current salt level and confirming the capacity, I will better know how much salt I need to add when the SWG arrives.

I will probably work on installing the SWG the better part of next week (after work).

Any suggestions or tips will be appreciated.

Thanks.

 

[mknauss]

You can give the salt test strips a try. Though you will find a Taylor K1766 salinity test kit is better.

At your high TA your CH is fine. If you drop your TA below 100 raise your CH.

 

[Mr Bruce]

What Marty said. K-1766 Taylor Salt Test $30 and it's the coolest test to do.

 

[Pflugerpool]

I come from a water quality background so I understand that test strips are usually good for nothing more than a poor approximation of any parameter, but I've been using the AquaChek salt strips made by Hach and I have to say I'm happy with them so far.

They're not a colorimetric method, so you don't have to squint at a chart and figure out if the color is Teal blue or Aquamarine. They have a little indicator stripe up the center, and when you read it, you just take that number and correlate it to a chart on the bottle for that lot and it gives you a salt level.

Reading them is not time-sensitive either - I've compared the reading on strips hours and days after I've used them, and once the test is complete, the reading is stable. They've have been 100% consistent from test to test and from lot to lot. And they agree with the level reported by the SWG controller.

 

[dradam]

I have a 19k gallon pool and use an IC40 SWCG. pentair- even though I oversized I still wish I had gone bigger. SWCG would likely run less and last longer and bring up FC more quickly.

 

[Backinsac1]

After carefully recalculating the pool volume, I've come to the conclusion that it is about 22K gallons and not the initial 18K gallons I estimated earlier. I'm glad I ordered the larger 60K capacity SWG.

Also, I will try the salt strips since they are already ordered. If the salt test strips don't work for me, I can order the Taylor K1766 kit later.

 

[Backinsac1]

Hi, just a followup.

I've installed the PL7703 (60K) system and have been using it for about a week and a half. I like it very much.

After installing the unit, I added salt to get to 3600 ppm and CYA to get to 70 ppm.

I set the unit for 30% with a pump run time of 6 hours. That only gave me about 1.5 to 2 ppm or so of chlorine.

Then I upped the SWG to 60% with the same 6 hour pump time. That gave me a minimum 3.5 ppm chlorine.

I adjusted the SWG to 45% and upped the pump run time to 8 hours. This gave me the same minimum 3.5 ppm chlorine. I also changed my pump time to night hours which saves me electricity costs.

I've been testing the water at night after the sun eats up the chlorine and before the SWG and pump come on and the chlorine lever has been consistently at 3.5 ppm.

I like that I don't have to add the liquid chlorine anymore. I do have to add acid as my PH tends to creep up, but I will work on that next. TA is 110, but the pool is still in balance because my CH is 170.

Pool is crystal clear and feels very nice. Overall I am happy.

 

[Backinsac1]

Also, forgot to mention that the temperatures in Northern California have been hot (90-100 F range). So if the SWG can keep up now, it shouldn't have any problems later on.

 

[blazer58]

I have the same swg... been sitting in the box since late May.
Hope to get it installed before end of Aug.
Glad to hear the post that it works fine

 

[Fuldo]

The TFP chart shows a minimum FC of 3.0 and a target of 5.0 for your conditions. I personally would shoot for a minimum of 4.0 and target 5.5 or so to give some margin in case of a malfunction. Going a little higher doesn't hurt and costs very little. I'm not sure why you're so concerned about pump run time, if your two speed pump is run mostly on low speed the electricity costs shouldn't be too high.

 

[Backinsac1]

Thanks Fuldo, perhaps you are right. I will up my chlorine to a higher level.

My calculations (via pool math and the cell capacity) show that I am generating 3.4 ppm chlorine gas/day at my current pump run time of 8 hours and SWG at 45%.

I can increase my pump time to 9 hours and set the SWG to 50% which should yield 4.7 ppm of chlorine.

My wife was concerned about excessive wear on the pump because before the SWG, we only ran it 6 hours/day. But after reading that many people run their pumps 24/7, I'm not as concerned about the wear and tear issue as much anymore.

 

[rowiac]

The SWCG uses less electricity than the pump typically (depending on the speed), so you may want to consider reducing pump run time further and increase SWCG output to make up for it. Even though the SWCG is run at a higher output %, you are running it for less time, so the wear and tear on the SWCG is a wash. I have been running my SWCG at 75% for 11.5 hours in the current hot weather. Since I'm not at 100%, I figure I can give it a little extra boost if needed due to bather load, etc.