Just bought a new house with a pool. Previously it had been maintained with trichlor pucks by the prior owners. I inherited a clear pool, but the CYA was >100 (probably close to 200). Being convinced by the common sense approach to pool maintenance I found here, I decided to take matters in my own hands, get rid of the pucks, fire the pool maintenance company (the prior owners were paying ~$5000/season for opening/closing, weekly maintenance), and save some $$. Plus, I like to understand how things work. So, if I was going to be through with pucks, it came down to SWG or Stenner. At 35K gallons, it seemed that our pool would be on the outer limit of what most SWG could handle (no ability to oversize the SWG by a factor of 2 or 3 for us). So the Stenner seemed like the most bullet-proof option. I've posted about my thoughts in a few posts, but I thought I would gather my approach in a new post in case others might want to try something similar.
Nothing too special about my Stenner install. I purchased the Stenner 45MPHP2 pump from Locke and will plumb it into my return line using a 1/2" x 2" schedule 40 T. I will use a Woods digital timer to control run time. The only thing that is out of the usual is my bleach storage. Pool math says that we will have to add ~72 oz of 12.5% bleach daily to bump FC by 2 ppm. I'm lazy and buying bleach weekly seemed like a chore that would foil my plans. I wanted to buy bleach in bulk and have to "refill" only once or twice per season. The rub is that bleach degrades with time (function of temperature and UV). Extrapolating from chemgeek's amazing work (http://www.troublefreepool.com/threa...perature/page2 post 23), I figured that low temperatures found a few feet down in the earth could provide a nice UV protected and cool storage solution for bleach.
I purchased a used food-grade HDPE 55 gallon barrel locally that has a sealed top and two-2" bungs for $35. I paid our gardener $100 to dig the hole and backfill with sand and gravel (see pic below). I paid ~$11 for a 2'x8'x3/4" sheet of rigid insulation that I used to wrap the upper part of the barrel (leaving the deepest part of the barrel in direct contact with the ground). The back fill with sand and gravel was to prevent frost heaving and distortion of the barrel. Finally, I built a frame to surround the barrel and attach a door to protect the top from rain and sun (pics below).
I put a couple gallons of Clorox into the barrel and let it sit for a day or so. I then inserted a teflon coated thermocouple into the bottom to see where the temperature settled. Currently, the air temp in lower NY was 56° F when I measured the temp of the bleach in the barrel which settled to 43-44° F (down from 55-56° F ambient when I added it). So far so good. The area in which the barrel is buried is mostly shaded so that should help as the season progresses. If my strategy works and i can keep the barrel contents between 40-50° F for the early part of the season and between 60-70° F for the latter part of the season, the degradation issue with bulk purchases will be an acceptable trade off for the convenience of only having to recharge my tank once or twice a season. If I use 72 oz/day I can get ~98 days out of a 55 gallon barrel. Our season is ~160 days. So I figure I can stock up early in the season with little worry and be good for 3 months and then buy enough to get me through the last 2 months. Since the ground will be the coldest in the early half of the season, degradation should be minimal. In the last half of the season, the barrel will be only partially full for the final two months and even if the barrel temp reaches 70° F, the degradation should only be manageable (e.g., at the end of the season, the 12.5% would be at ~10%). I'll have to see how the temperature maintains through this season (hence the $36 investment in the thermocouple).
Obviously not a solution for everyone, but for those who have the space near their equipment pad to bury a tank, I think it holds some promise. I'll do my best to keep the forum apprised of my progress.
Buried 55 gallon tank adjacent to my equipment pad.
I'll post other photos in a subsequent post...I'm getting an error message when I try to post another photo.