Hard water - Kati Ani and house water softener

[gaijin]

Hi all!

My first post.

I have very hard water. But we really want to keep discus. I'm not going to get any until I'm comfortable keeping the water first.

I'm using a medium size kati-ani setup attached to a pipe before it hits the house water softener and get about 800l before the resin had gone completely red. Question one - does any one have english instructions on how to recharge? I've got french if anyone needs.

Question two. I've searched all over but can find the answer to this one: Should i try processing water after its been through the housewater softener? I've heard that the house softeners add way to much salt (I can taste it). And will the Kati-ani take out the salt and if so put me back were I started (little water before needing to recharge)?

Thanks in advance for your thoughts.

J

[Apistomaster]

I have wondered about some of the same questions you raised myself.
I know it is not that simple to answer them because there are many different possible combinations of cation and anion deionizing zeolites. It seems like the right place to begin is with a accurate analysis of the source water.
I think the types of zeolites that are the most effective at removing most of the calcium, magnesium sodium and chlorides and sulfates require strong acids and strong bases to recharge.
If you can afford the use of these deionizing systems then the resulting water makes for longer RO membrane life or even the complete elimination of any RO in the system resulting in a no waste water purification system. Is it cost competitive with a RO? I don't know.
I might be wrong, but for some reason, I think I read that the common aquarium RO filters are not designed for optimal sodium chloride rejection and that the milder cationic zeolites that are widely used in home water softeners do leave high sodium content as magnesium and calcium ions are exchange with sodium ions. These are the type that are recharged using brine solutions.
The home systems may still be helpful in reducing the work and extending RO membrane service life.
I have never really carefully gathered all the information and cost of equipment and replacement zeolites of the stronger types that require dangerous chemicals to recharge to figure out the cost benefits. I think usually one just swaps the used zeolites for freshly recharged rather than doing the recharging yourself. It otherwise gets you into toxic chemical disposal costs and possible injury.
I suspect that if all the costs are carefully tracked the bottom line is that just using an appropriately sized RO system, even if the membrane has to be replaced more frequently where your water is so hard will still be the most cost effective method of getting pure water.
It will be interesting to hear from others who have already dealt with this issue. I am revamping my RO system. It is actually still a work in progress so maybe something will come up that may improve upon what I am putting together.
I already wish I had purchased a higher volume RO unit. One rated for 300 gal per day or more instead of the Kent Maxxima Hi-S 60 gpd unit I bought a couple years ago. I can go through much more water than that even with 110 gal of product water storage capacity.

[Don Trinko]

I have 2 house type RO systems. One reduces tap TDS from 500 to 700 to 22, the other reduces TDS to 15. Don T.