We recently bought a house in which the previous owner had installed a Culligan softener system with not only brine and resin tanks but also a chlorine tank with a pump. There isn't a Culligan representative remaining within a 50 mile radius of the house, the ones outside of that range aren't willing to come without a huge fee (understandable) or at all.

The salt part is easy. What I don't know is what kind of chlorine solution or pellets or powder or [???] should I be adding to the chlorine tank? Google is usually my friend, but not on this issue. I don't want to just dump a bottle of Clorox in there, since I don't know (a) if sodium hypochlorite is the correct chemical for use in water treatment without poisoning us all to death, and (b) what other odd chemicals are in Clorox that will poison us all to death.

Our water is sourced from a well that is by itself fails on lead (0.023 mg/l) and is heavily laced with iron (20.4 mg/l). What can almost not be made out in the pictures below is a 10" carbon pre-filter (you can see the bottom sticking out from under the controller on the resin tank). The pre-filter does a pretty good job of removing the iron, though we have to replace it every 2 to 3 months.

There are two tanks that are obviously labeled Culligan; the third is of a slightly different color; no brand name on the tank itself, but written in blue ink are the words "gallon chlorine" (possibly a faded numeral before). picture of entire water treatment plant enter image description here

On the top of the tank marked "chlorine" is a pump: enter image description here

  • We need a bit more information - could you give a model series or model number? Why do you think it is a chlorine tank and is it Culligan branded? do you have a picture? Is your water from a well or other non-treated source? You are right to not put just anything in the tank as chlorine exposed to water can cause a vigorous reaction - if the tank is sealed, if could burst if the wrong form is used.
    – Ben
    May 19, 2015 at 13:18
  • Thanks, Ben - I've added the information and pictures as requested.
    – JackT
    May 21, 2015 at 0:31

4 Answers 4


This looks very similar to a pool chlorine feeder - these could use cal hypo or sodium hypo, either way you would need to know the concentration to mix and the dosing for your qty of water to treat. Not sure we'll be able to answer those questions directly.

Sodium hypo - bleach - would be the cleanest option, but also will become ineffective the quickest.

Cal hypo is granular (and cheapest) and has the most shelf life, but you'd probably want to source food grade supply for long-term use.

Concentration of chlorine would be determined by the qty of water to be treated at one time, level of final level of chlorine needed for decontamination, how the chlorine solution is dispensed (continuous or on demand) and how much chlorine is dispensed at any given cycle.

Chlorine would only be used to correct organism growth not other chemical/mineral constituents of concern.

Due to the health risks, I 'm not sure how much I'd trust free advice at this point. Spend the money and be sure this is set up properly. Your health is worth it.

  • I have no idea what you guys are talking about; +1 for the last line.
    – Mazura
    May 21, 2015 at 2:50

This actually is a chlorine tank. I have one, I personally buy the pool chlorine at a pool supply store to put in mine, but you can just use regular chlorine bleach. It's slightly cheaper to do from the pool store. I was actually searching to see if anyone just tossed tablets in their tank instead of feeding it. Usually you should put about 1/4 amount of chlorine to water, there should be a spigot on your holding tank where you can test and ideal amount should be in the same range as your pool. After it goes through the filters though, there should be zero. However in looking at your setup, it seems like yours goes directly through the filter and then into the tank so I don't know how exactly you'd test percentage on yours?

  • I test the percentage by running the water for several minutes through a utility sink faucet (next to my washer/dryer and maybe 15 feet from the tank) and then using a test strip. I need to get a specific type of test strip that will show between 1 and 5-10 ppm max; you want the drinking water percentage to be below 4ppm (I shoot for 2ppm). Regular pool test strips start turning blue at 10ppm and then give you a range to something like 50ppm; that makes the pool test strips useless because when they start showing blue, you already have too much chlorine.
    – JackT
    Sep 11, 2020 at 19:56

This looks like my former house. If it is, I paid Culligan to install it. I used 50% liquid chlorine from pinch a penny pool company and 50% of water. The inside spigot, I used a water hose on for the salt water kidney shaped pool. I converted the pool to salt water. It was chlorine. The outside fiberglass tank, you have to open the valve and flush the backwash water out.


I have a water softener just like yours , mine is a little more newer , and I have twin tanks. I put in 7 lbs of soda ash and about a quarter of a gallon of hypochlorite every time I fill my 35 gallon feeder tank. That was how Culligan instructed us , when we purchased new. Water has been great and no issues. Hope this helps!!!

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