How many gallons out of an RO-DI unit?

[stratmaster]

Ok so I've had my Coralife Ro-Di unit for little over two weeks now. Only thing is I've only used it for about 75 gallons so far and already the Ro-Di cartridge (which started out a green color) is not almost completely covered by brown stuff. Does this mean it's time to change it out already? I don't understand if that's the case. I was told you can get more then 75 gallons out of a DI unit.

Also are the DI units expensive? I sure hope not. I mean I was paying $1 a gallon for RO water so it'll still be cheaper even to pay for one every now and then. I just hope it won't be every week. Maybe I'll post a pic up later of how brown the DI is.

Steve

[AMDPhenomX4]

Aslong as your TDS is zero its fine.

[melosu58]

It`s still OK. I usually go about a yr with mine. I have a 50 gpd. As mentioned above as long as it test at 0 you`ll be OK.

[CaptainAhab]

Not sure where you keep it, but it's recommended to keep it out if direct sunlight. Longevity also depends on the quality of your source water. The worse it is, the less your filter media lasts.

[Kurt_Nelson]

You said your RO-DI cartridge... ?

You've got an RO membrane in one canister, and DI resin in the last canister in the system. Which is it that is turning colors?

If it's your DI cartridge that is turning from green to brown, that normally means your DI resin is shot. As CaptainAhab mentioned, how long the DI resin lasts will depend on the TDS of your source water. With really high TDS, you might blow through the resin that fast if your RO membrane is only, say, taking out 95% of the junk. But with low TDS (say less than 100), I'd expect it to last longer than that.

But yeah... if the output is at zero, you're still OK. Even after the color changes, there's still a fair amount of life in them.

[stratmaster]

Originally Posted by melosu58

It`s still OK. I usually go about a yr with mine. I have a 50 gpd. As mentioned above as long as it test at 0 you`ll be OK.

I'm not sure if it's you but I believe we have the same RO-DI unit? The Coralife 50 GPD RO-DI unit right? I think you mentioned you had it when I was asking about how good it was. I actually really like it! Very simple and it produces plenty of water for me.


Coralife Pure-Flo II - 50 GPD 3 Canister RO/DI System

And I do apologize, I did mean the DI unit. It's turning quite brown only after a couple uses, but you guys say for me to test it and make sure the TDS is at 0? What is TDS?

[melosu58]

Reverse Osmosis Aquarium Water Quality: Maxxima RO/DI Units

This is mine

[stratmaster]

Ah ok it wasn't you I guess. There's a member on here who mentioned they have the same unit as me. I really do like it I'm just disappointed how the DI cartridge looks so dirty already.

Steve

[HN1]

I have the same unit. Who cares what the cartirdge looks like if the output is quality? lol

Get a TDS meter to be sure, but don't sweat the appearance. The more bad stuff it takes out of the water, the more that will be visible. I'd seriously worry about a filter of any kind, for any application, that stayed pristine looking.

[stratmaster]

I guess I'm just thinking like a filter. Typically as the cartridge gets dirty, you either replace it or clean it out. I don't really care either way what it looks like IF it is actually working still.

And I'm still confused on what TDS is lol. Would it actually hurt to wash it off?

Steve

[InfernoST]

TDS = Total Dissolved Solids. The meter they are talking about measures the TDS in the water, they have meters that you can install in your unit the measure the input TDS and ouput TDS, Ideally it should be at 0 on the output side of your RO/DI unit, if not it's time to change your blocks. If your unit came with a flush kit this will allow you to safely clean out your membrane. As for the rest Kurt Nelson covered it above, The higher your source TDS the quicker you will be going thru DI resin.
In short TDS is the measurement of the amount of minerals and metals contained in your water.