[saltysteve]

what are you guys using for R/O DI resign? im going through it alot. i usually buy it for $12 a bag and it fills one canister. i buy it from the filter guys. is anyone using anything just as good but cheaper?

[saltysteve]

bump..... ....

[pogodzib]

I get mine from filter guys. You can buy more bags at a time and get a lower per bag price, but before you do that, do you know that the rest of your RO/DI unit is functioning properly? What is your water's TDS as it enters the unit, prior to the RO membrane, and after the RO membrane? If everything is functioning normally, the water entering the DI resin should have a low TDS reading so the resin should last for several hundred gallons.

[saltysteve]

after the ro the tds is around 2 or 4 sometimes.
after the DI its 0
i do have well water so i think im going through it faster

[pogodzib]

If your TDS is 2-4 after the RO membrane, then your filters seem fine. Also, since you have a TDS meter, I'll assume that you are changing out the DI resin when your TDS starts to rise, and not when the resin color changes. Correct? Often, the resin will start changing color when the resin still has remaining life. Secondly, when you store the resin, make sure that it stays in a plastic bag in a cool, dark place.

[saltysteve]

hmmm- i only changed one tube of resign but i didnt wait for it to show a raise on the tds meter before changing. thanx maybe thats my problem. k well untill i see a change in the numbers ill leave the resign . i m ordering 4 bags of the filterguys color changing resign for $42 and a auto shut switch for my aquatec booster. i hope this all works out and thanx again for that info

[pogodzib]

Your welcome. I (and most other reef keepers) usually try to change my resin when the TDS rises to 1 or 2 after the water passes through the DI resin.

[saltysteve]

hmmm now im starting to wonder why i have a six stage with the 2 DI cyclinders? if one fills up and then the other turns color too whats really the point? not changing them as much? right now both are brown and im still getting a 0 reading ( the second one just turned brown). I guess ill wait and see

[saltysteve]

oh and do you guys recommend a auto flush switch for $50 to automatically flush before it begin topping off? It also runs for 18 secs every hour. Is this worth getting?

[pogodzib]

Using two DI resin stages after your RO membrane isn't necessary, but there are some people do that. The only way of knowing if the first DI cartridge is used up though is by having a TDS meter installed between the two cartridges. Are you sure that you have two DI resin cylinders? Most 6 stage units have the fifth stage being DI resin, and the sixth stage a carbon (taste) filter. Although the fish don't need the taste filter so I always bypass that for my tank water and keep it inline for my drinking water.

Most people don't use an autoflush on their RO units, although the initial water that does through the unit is the worst water. If you do use any autoflush, place it between the RO membrane and DI resin if possible. I do like having a munual flush kit installed though so I can flush my RO membrane on my own periodically. They cost around $10 at most places.

[saltysteve]

so what would be the point of two DI resin stages ?? Also if my auto top off kicks in every one to two days that means every 1 to 2 days some really bad water is flowing into my tank? i think at that point it might be a good investment. How bad is that first few seconds of water? my tds doesnt show a bad read when it first starts up at all.

[pogodzib]

The second DI stage would be there primarily to make sure that you are always getting zero TDS. Many times you'll get a TDS reading of 1-2 when there is still a good chunk of DI resin that is good, but the water is flowing through other areas of the cartridge as well where the resin is bad.

The water that comes out initially isn't that bad that you need to worry about it and the DI resin will remove the bad stuff anyway.

Is your RO/DI unit hooked up directly to your auto top off system? I wouldn't recommend it because if your auto top off valve/float were to fail, you'd have an endless supply of water going to your tank, thus causing an overflow with water on the floor and a low SG in your tank. Having a bucket with auto top off water and filling the bucket/trash can up when needed is a better method.

[saltysteve]

yes it is hooked up directly but im not worried since im using a solenoid to cut the water off. the lines are off when the power is off and the solenoid opens when it gets power. ro/di pours right into sump automatically. still working out one small issue with powering off the booster pump