What kind of RO/DI system to buy?

dmax

Member
Wondering what is a good system to purchase? My dad has put one in at his house under the sink. It came woth an external spout that you mount at the sink. I think it is pointed more towards home use rather than the aquarium.
Wondering if a system like this will work or do I need to get something else???
Thanks
 

sly

Active Member
Yes it will work... I've used one for years. They are the same thing... it's just that if you get one for an aquarium you will get fewer features and spend a lot more.
I have a Whirlpool RO unit with an external 2 chamber DI filter. TDS meter shows 3ppm coming out of the RO stage and then 0ppm when that water comes out of the DI stage. 0ppm is 0ppm... doesn't matter if it's for drinking or for the fish.
 

dmax

Member
I have seen one at lowes for like 160.00. But it also is only an ro system. But i am able to hook it up to my fridge and to the sink attachment.
Would I need to buy a DI filter to add to it?
 

dmax

Member
The one at lowes is a whirpool.
Would this be a good system to buy?
I like the fact that I can use it on the fridge for ice and filter dispencer.
But I dont really like that the canisters are white (not clear).
 

fishfreak1242

Active Member
Check out bulk reef supply. They have great RO and RO/DI units. I just bought one from them and I LOVE it. I get 0 tds even before the DI.
 

sly

Active Member
Originally Posted by DMAX
http:///forum/post/2787500
The one at lowes is a whirpool.
Would this be a good system to buy?
I like the fact that I can use it on the fridge for ice and filter dispencer.
But I dont really like that the canisters are white (not clear).
The one from Lowe's is a very good system. It has a storage tank and provides more than enough water to top off my 72. It does not come with a DI filter. I bought one separately off the internet and just hooked it in after the RO filter. It is a very large capacity 2 stage DI filter and so far, after a year and a half, I have not had to replace the filter media.
I bought an inline TDS meter that hooks up to the plastic hoses coming out of the RO filter. It has 2 probes and so I have one coming before and one after the DI stage. This lets me see both the TDS of the RO water and the TDS of the DI filter section. This way I will know exactly when the filters need replacing... So for me I don't mind that the filter housings are not clear. The TDS meter is far more accurate.
 

dmax

Member
Thanks Sly.. What does your TDS meter read after the RO unit, Before the DI?
Just curious. Do you have to get it down to zero ppm???
Or would the RO work fine on its own?
 

fishfreak1242

Active Member
Originally Posted by DMAX
http:///forum/post/2788569
Thanks Sly.. What does your TDS meter read after the RO unit, Before the DI?
Just curious. Do you have to get it down to zero ppm???
Or would the RO work fine on its own?
It would be best to get it down to 0 ppm. But if you just have like a FO or maybe even a FOWLR, then just a RO would work. But if you plan on having a reef tank it would be best to get a RO/DI.
 

sly

Active Member
Originally Posted by DMAX
http:///forum/post/2788569
Thanks Sly.. What does your TDS meter read after the RO unit, Before the DI?
Just curious. Do you have to get it down to zero ppm???
Or would the RO work fine on its own?
After the RO stage= 3ppm
After the DI stage= 0ppm
I like it better than building your own because all I have to do is go over to Lowe's to pick up a new cartridge rather than having to order one online... perhaps a small difference but it's a little more convenient for me since Lowe's is only 6 minutes away. However there can be nothing more satisfying than to have something that you built and knowing that you did it right...
I hardly ever do water changes so 0ppm is very important to me. You want to get it as low to 0 as possible... If you do frequent water changes, have a low bio-load in your tank and don't have tons of delicate coral then you would be just fine with a higher TDS. Most RO units without the DI stage can not deliver 0ppm water even when new, but that is fine for most tanks. It's still probably purer than bottled water.
 

dmax

Member
Thanks guys.
You would want the 0 ppm for the corals and anenomes right?
Its not so much for the fish?
I have some zoas, mushrooms, a BTA, and open brain.
They do fine with the water from my fridge that is filtered.
Im guessing they would do better with the RO/DI system?
Grow better?
 

fishfreak1242

Active Member
Originally Posted by DMAX
http:///forum/post/2788750
Thanks guys.
You would want the 0 ppm for the corals and anenomes right?
Its not so much for the fish?
I have some zoas, mushrooms, a BTA, and open brain.
They do fine with the water from my fridge that is filtered.
Im guessing they would do better with the RO/DI system?
Grow better?
Yeh it would be best to have 0 tds water from a RO/DI system.
 

aquaknight

Active Member

Originally Posted by DMAX
http:///forum/post/2788750
Thanks guys.
You would want the 0 ppm for the corals and anenomes right?
Its not so much for the fish?
I have some zoas, mushrooms, a BTA, and open brain.
They do fine with the water from my fridge that is filtered.
Im guessing they would do better with the RO/DI system?
Grow better?
I doubt they will actually do much better, if you aren't having problems currently (no algae blooms, etc). More of what a RO/DI system is, would be protection/insurance. There's no way to regulate if your fridge water happens to leach out some extra copper particulates that would kill your corals. Or if your city water had some extra phosphates in the water from a recent storm, that a standard fridge filter doesn't remove, and induce a ton of algae to pop up in your tank.
I always recommend units designed for aquarium use, as any decent LFS with have 'standard' filters that will work for my system. With a RO/DI
system, yes, you really only want 0ppm TDS, or 1 or 2 ppm TDS at the maximum. The DI will/should remove ANYTHING that is left in the water, so when you start to see readings, you know it's time for a change as it's releasing the crap back into the water.
Sly, that's some fantastic water coming out of the RO, what's the TDS of the incoming water, before the unit?
 

sly

Active Member
Originally Posted by AquaKnight
http:///forum/post/2789806
Sly, that's some fantastic water coming out of the RO, what's the TDS of the incoming water, before the unit?
I wish I knew... I'll pull the probe out and test the tap water and see. We do have some pretty good water here. I have a whole house sediment filter before the RO/DI system as well.
 

dmax

Member
Thanks alot guys. I Think I am going to go to lowes and get the whirpool and add the DI system for the tank.
 

aquaknight

Active Member
Originally Posted by Sly
http:///forum/post/2790270
Ok... I just checked it. Tap water is ranging from 73-85 ppm. Not bad.

WOW! That explains it! I was thinking you had some good water coming in, but dang 73-85 ppm tap water... I'm at 200ppm myself. I've heard of people out west with heavily treated water at 600ppm!
DI's last 3 months and RO membranes 6 months out there!
 
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