Start with what your plants need and back it out to figure how much total volume you need as a reservoir. Perhaps you should take one dry container saturate it with a known amount of water then see how much you recover after it is stops dripping. The difference in the two will be how much your medium holds. times however many containers you have and you have a basic volume required for each plant. area of pipes times length gives you volume of the pipes. add it all together and double that for container size. but for rez quantity only add 25% as starting point. loop time is fairly inconsequential since it's a continuous cycle. you just want to make sure to keep liquid in the lines under the appropriate pressure.

ummm...those tanks belong to Suburban Propane unless you purchased them from Suburban. They are 120's, the one you show the data stamp on was built in 1969, and is several years out of date on it's E inspection. I would value the tanks at $150-200 each if the bottoms and all are good. 60% = roughly 72 gallons in a 120 (percentage x 1.2) and you should be able to get current market price for the gas as it does not go bad. So, if propane is $3/gallon shoot for $400-425/per tank w/gas. Again, the tanks need to be re-inspected visually by a qualified agency (propane dealer) and the bottoms need to be checked for pits, by a qualified agency. They are DOT tanks, and several things like rust, pits, dents, gouges, etc. can make them worthless.

We have a 500 gal underground tank used for cooking, dryer, and gas fireplace. A fill-up typically lasts us 2-3 years. It depends upon fireplace use more than anything else for us. In the colder months we'll use it for 3-5 hours a day every day. That amount of use for about 4 months typically uses about 1/3 of the tank. When we had it connected to the pool heater, we used a tank per year. Our main heat source is geothermal with electric backup. I don't know how the water heater would impact use of propane. My guess is that you might use 1/2-3/4 of a 500 gallon tank/year. I think the 1000 gallon tank is probably overkill. You can do a partial fill in the summer if you want to take advantage of lower prices and the tank isn't empty.

Salt usage and capacity per cubic foot of resin isn't linear. In other words, it takes a lot more salt per cubic foot of resin to get that last bit of capacity. This is the chart I use. The complications with whole house carbon filters come from free chlorine vs chloramine. Free chlorine can be filtered out by a standard carbon filter, while chloramine needs a catalytic carbon filter. Chloramine is chlorine combined with ammonia which is replacing chlorine as a disinfectant. Byproducts of disinfection with chlorine include trihalomethanes which is what is driving the move to chloramine as a disinfectant. To make that point more clear, open up a bottle of bleach... is the smell overpowering and hurts your eyes, etc even in this relatively concentrated form? No. It's not until the chlorine combines with other molecules that it becomes chloramine and then you really smell it. Swimming pools smell strong because of chlorine mixed with organic materials in the water...(as in pee) not because of chlorine itself. I know that this will fall of deaf ears, but I think the residential water filtering industry has gone off the deep end. I have no problem with a basic carbon filter to clean up taste and smell of drinking water, not to mention cleaning up some VOC's and such. I think it's a bit much when people are worried about showering in water with small amounts of free chlorine. In terms of actual risk, I think that removing all of the residual disinfectant prior to a resin bed is probably more of a health risk than showering or bathing in water with some free chlorine. Many people raise the issue of bacteria growing in filters / resin beds / even water pitchers after all of the disinfectant has been removed by a carbon filter. Most of us have spent time in a swimming pool - and Olympic swimmers spend a lot of time in swimming pool. Other than a possible link between absorbing chlorine from the water and being gay, I haven't seen any serious health effects for Olympic swimmers and divers (ok, I am kidding). Put in your water softener. Put a cartridge carbon filter / KDF 55 filter on your drinking water. If you need to loop in a whole house carbon filter later you can - but I don't think you will need to. Just a tip, If this is a DIY job, I've been happy with units I've purchased online from ABC Water. I have no connection to them other than being a satisfied customer. They can put together any system you want. They sell them cheaper through Amazon than on their own website.