Thinking I'll spend some coin to replace the cartridges in my RODI unit as I'm unsure of age, and dont have access to a TDS meter to tell me if they're stuffed or not.

Wheres the best place to go in CHC to buy them? Will I need to take the old cartridges in?

Its a 3 stage filter, RO Prefilter, DI, then RO again (if that makes sense, I'm not too clued up on them).

Recently tested the final water product that it produces for PO4 & NO3, and it shows a reading of 0 on both.

Recently tested the final water product that it produces for PO4 & NO3, and it shows a reading of 0 on both.

So does my tapwater

(teeheeeheee)

Mine doesn't

0.03 for PO4

I'm jsut concerned that if the filters are stuffed, that it would be worse putting the produced water into the tank than it is to use the tap water?

I have considered going back to using tap water along with a heap of PO4 remover, like yourself conch

For testing purposes, tds is the only truely reliable way to know how the cartridge is performing.

Basically you test each stage seperately.

Which requires a TDS meter, which I dont have, and not sure I want to spend $$$ for a 1 time use. I see a local reseller has one for $69 odd, but as mentioned, is it worth it for 1 use? And how accurate is one that cheap going to be? $69 could go quite a way towards replacing all the filters?

I'd have thought you'd have replaced them already if you were going to. I must have contaminated the filter with my procrastination and you caught it.

You might be able to get your TDS level tested for free at a swimming pool shop? The one I used to work in up here tested for TDS... Can always try

I'd have thought you'd have replaced them already if you were going to. I must have contaminated the filter with my procrastination and you caught it.

LOL! Is that what that strange thing was that came in the box with the unit?

I brought a TDS tester last time i did my RO. It cost $135 for the tester which was worth it because it would have cost me the same for the membrane filter which did not need changing. It my take a few years to get my moneys worth out of it but at least i know for sure now when to change it.

Sweet! I thought it should still be good.

What skuzza said.

Don't forget when you do test the water that you should perform the test after the RO stage and before the DI stage. So you will need to break the link temporarily.

Otherwise you might get a 0 reading at the end of both which could simply mean that the resin is working overtime to counteract for a poor membrane.

In my unit the tap water enters with a TDS reading of around 130 which drops to between 50 and 60 after passing through the RO and then finally down to single digits when passed through the resin.

Personally for $69 I'd buy one. I have 2 TDS units, one which measures to an accuracy of 1 in 100, the other to 1 in 1000. The first unit cost about $200 and the more accurate unit about $300.

I only ever use the first unit now; and I do use the unit regularly every month just to check that top off water going in remains as pure as it can be epxected to be.

OK so got a cheap TDS unit.

The unit was spitting out water @ 17ppm (tap water here in CHC read 45ppm)

Replaced First RO cartridge, changed it to 8ppm, replaced DI cartridge, 0ppm

Seems i'm unable to test the tank water tho, the unit reads ERROR, and thats the same for my saltwater storage aswel.

Oh well at least I know i'm using excellent water now

you cant use a TDS meter to test saltwater as the has to many minerals in it

TDS is for freshwater only.

I would stick with chch tap water as it is pure.. where did i read that..

:lol:

i was waiting for you to say that reef , at least finally answers the question on chch water. BTW where did you get your tds meter matt? and did you go for an inline unit or a 'pen' style meter. I'm desperate to connect my di unit up to the tap but haven't managed to find a faucet adaptor to connect it yet. I was thinking of grabbing one of those pen style tds meters of ebay

Noone likes a skiter reef

Its one of the pen type ones. Just a cheapy