My first post here. Been reading up and using the pool calculator for a couple of months. I decided to take over from the "pool guy" and take responsibility for the pool myself, so I needed to read up on what to do. This site is perfect for a guy like me!
Anyways, I decided to go for a SWG system (Circupool RJ-60 plus). Reading about adding salt suggested that it might take 24-48 hours for it to dissolve in the water. I didn't want to wait that long so I started out with a "mud mixer" attached to the end of my drill to stir up the water/pellets in a 5 gallon bucket. This actually worked pretty well but it was going at the rate of 50 pounds per 30-45 minutes and it meant I had to stand there running the drill and changing out batteries (which isn't good for the drill either!!). Just for kicks, I put a couple of pellets in front of a pool return jet on the steps and they dissolved pretty quickly. Then I thought... hey, how can I exploit this flowing water thing?? I have a pump (sweeper booster pump) and hose (sweeper hose) and a bunch of bags of salt. This is what I came up with...
1. A clean 5 gallon bucket
2. A booster pump for pool sweeper (Polaris 280 in my case)
3. The appropriate # of salt pellet bags to raise the salinity up to 3500 ppm (note: my pool already had 1300 ppm salt. GLAD I TESTED FIRST!!)
4. A few big zip ties
1. Scoop the bucket in the water to partially fill it with pool water to keep it from from floating up.
2. Place the bucket on a pool step such that the top of the bucket is at or above the water level of the pool (if you don't have a step, maybe stack up buckets in the shallow end?)
3. Disconnect the sweeper hose just above the sweeper's reverse thruster (i.e. you want just the hose end without the thruster/sweeper attached). If you can, do it such that there aren't any of the floats near the end of your disconnected hose. Having a float down in your bucket will cause it to float and cause problems.
4. Put the hose down into the bottom of the bucket so that it makes a partial coil at the bottom of the bucket to create a swirling action as the water flows.
5. Zip tie the hose to the bucket handle to keep if from coming out as the pump pressure tries to make it fly around like a fire hose out of the bucket. This part might be tricky, but it can be done.
6. Fill the bucket with salt pellets pretty much all the way to the top of the bucket, just before they pile over the top edge of the bucket.
7. Now comes the fun part... turning the pump on. You might try running your filter pump on high (without actually running the sweeper booster pump). My main pump actually puts out a good bit of flow through the sweeper hose with the booster pump off. Doing it this way, you slow down the process a bit but it's much more manageable. If you are feeling frisky, you can turn the sweeper booster pump on. Just be careful that you have the hose properly secured to the bucket or you will have water spraying all over the place!
Now your cup (bucket) runneth over with salt water with barely any effort on your part. Sit back with an adult beverage and watch it work.
Every 5-10 minutes, check the level of salt pellets in the bucket and top it off as necessary. With my booster pump on, I went through a 50 lb bag of pellets about every 5 minutes or so. With just the filter pump running, it took about 10-15 minutes to go through a 50 lb bag.
Hints and observations:
Move your bucket around onto different locations to distribute the salt around initially. Near return jets are even better. Probably good to be away from the pool drain and skimmer to avoid a high salt dose to the pump and other equipment.
I asked my local pool store to measure the water before I started this process. They said the salt was ~100 ppm. I'm glad I bought a good salt tester kit (Taylor K-1766, 200ppm drops type)! I thought I'd verify their measurement with my new kit and was astounded to find that it wasn't 100 ppm but rather 1300-1500 ppm! Yes, I triple checked it with my tester kit.
In order to be more accurate with my salinity level testing, I doubled the volume of pool water (20mL rather than 10mL as indicated) and used 2 drops of the yellow chromate stuff instead of the 1 as indicated on the instructions. That way, each drop of the silver nitrate reagent is equivalent to 100 ppm salt, rather than 200.
I do recommend using less salt than you think at first. I initially thought I'd need ~1000 lbs of salt to get to 3500 ppm. As it turns out, my pool isn't really 35000 gallons, it's closer to 26000-28000 gallons. Also, there was already ~1300 ppm of salt in there. We bought the house just over a year ago and I don't have much history of the pool. Either really sweaty people bathed in it all the time or somebody added some salt in the past.
You can use the salt addition process to approximate the volume of your pool. Since ours is a freeform pool, it's hard to estimate the volume using a tape measure and simple volume calcs. I had initially over-estimated it at 35000 gallons. Using the pool calculator from this site, and my conservative estimate on how much salt to add, I found that 350 pounds of additional salt brought me from 1300 ppm to 2800 ppm. I plugged in the initial 1300 and target 2800 (that I measured after waiting 2 hours with pumps and sweeper on full). Then adjusted the pool volume at the top of the calculator until the pounds of salt to add equaled the amount I actually added. I hope that makes sense.