RO Filter

[depeche]

I need to get a small RO filter for making fresh water. I'm tired of getting buckets of it from the LFS. I have a small (35 gallon) reef tank, so I don't need tons of fresh water. All I'd really need is maybe 1-2 gallons a day (if that), and maybe some extra for drinking water.

Can anyone suggest a good filter to get for my situation? I don't want to get stuck with one that over-charges for some sort of proprietary replacement filters. Maybe something from the local hardware store?

I appreciate any help that you can give me.

Thanks!

 

[Porkfat]

I got a Mighty Mite with DI Added Works good 0 TDS small volume, replacement filters run like $35.

You could probaly find one on ebay like this one for cheaper (shipping is a little expencive though). I went with the smaller unit because
1) I don't have a lot of space (I'm a student and I move around too)
2) I didn't want to have to replace all those filters.
3) I don't need that kind of RO/DI generating capasity

Lots of choices out there, choose one that works best for you.

~Brandon

 

[chris&barb]

http://www.buckeyefieldsupply.com/

 

[clayswim]

Both companies above carry quality products, just don't order the 100gpd unit. Both the 50 and 75gpd units use the high-rejection membranes. In my personal opinion the eBay systems don't quite match the quality and construction of the better brands like AirWater&Ice or Buckeye.

Clayton

 

[Blazer88]

I was told you can get the ones from ebay with the 75 or 50 gpd membranes rather than the 100, you just have to ask them. Are there any real difference in quality as long as the TDS meter reads 0?

 

[mattseattle]

many people swear by buying the more expensives AirWaterIce units or others but I am not one of them.

I bought a 100 gpd AquaSafe unit off E-bay. Ed, the owner is in Blaine, Washington so shipping was quick and he's awesome to work with. The unit was 75.00 shipped and it arrived in a day. My incoming TDS is 25 and the TDS going out of the RO membrane is 0. I've had the same DI cartridge for almost a year now without switching it out. I probably should switch it soon just to be safe but it's not exhausted by any means. The quality of the canisters and tubing are high quality. It's comparable to the old Kent RO unit I had which was 300.00 when I bought it. Stupid me for not knowing.

One thing I did do was to swap out the carbon filters on the AquaSafe unit with the Chlorine Guzzler from Buckeyefieldsupply. With the Aquasafe unit you get a 6 stage filter so you have 3 pre-filters then the membrane then the DI cartridge then a polishing filter. I don't use the polishing filter as I don't see a need for it for aquarium water as it only effects taste. With the 3 pre-filters I put in a sediment filter then 2 carbon filters before the membrane. Even with that I am still under a 100.00.
That is my .02 cents worth. I say buy one off e-bay and you won't regret it.

 

[Ed Hahn]

I recently purchased a RO/DI unit. I have a Culligan RO unit plumbed into my house. I compared my Culligan RO unit to the Typhoon III RO/DI unit I now have with a TDS meter. Culligan showed 5 TDS. The Typhoon shows 0. Both units have new filters.
I hope this helps.
Ed

 

[mattseattle]

hey Ed - what is the TDS of your incoming water? It would be nice to see a comparison of TDS around the state.

 

[Ed Hahn]

I think it was 252. I am at work still. I will check and get back to you.

 

[clayswim]

My TDS here in Roy is 52. It's a private well.

As for the water quality differences between eBay and the others... Both AirWater&Ice and Buckeye use Filmtec membranes, and as long as the eBay units use the same membrane (which they normally do) you're going to see the same water quality in terms of TDS; since the pre-filters don't change the TDS. The quality difference I was referring to was the construction of the parts; like the housings, pre-filters, brackets, etc. Sometimes the eBay units are high-quality, but sometimes they're not. They usually use the throw-away DI cartridges too, instead of the refillable 10" housing cartridges. That ends up costing you more money in the long run. Again, it's just a personal preference. The eBay units will still provide your tank with pure water.

Clayton

 

[Blazer88]

I bought a Kent Maxxima unit from someone here on the board, I just see a ton of people using the ones from ebay. My TDS in Bellevue I think is 38, I haven't tested since the first day I got my meter so I can't exactly remember. I too grew tired of having to buy my water elsewhere (Safeway) and am very happy I ended up with an RO/DI.

 

[Ed Hahn]

hey Ed - what is the TDS of your incoming water? It would be nice to see a comparison of TDS around the state.

Matt,
My TDS directly from Tap is 259 Total Disolved Solids.
Ed

 

[mattseattle]

thanks Ed....

I just tested mine and it is 35. Guess we definitely have pretty clean water.

 

[depeche]

Thanks all, I appreciate the info!

Why is it that you're not supposed to drink DI water btw? And what exactly does de-ionizing the water do that's beneficial for the reef inhabitants?

 

[depeche]

Clayswim answered my question in another thread....

Since suspended particles can't transfer electricity, but dissolved particles can, a simple test of conductivity tells us how many dissolved salts are present in the water. The problem with this test though is that it isn't complete. Not all undesirable compounds will conduct electricity, which means even our RO water that tests zero TDS can still contain compounds that can harm our livestock. RO membranes will "on average" remove the percentage given above. In reality the percentages are different for each compound. For example, copper is almost completely removed; but sodium is only mostly removed, and ammonia isn't removed hardly at all. For these reasons I highly recommend a high-rejection-rate membrane; and I also recommend you use a DI cartridge to mop up whatever gets past the membrane. Don't be fooled by TDS monitors, RO-only water is not completely pure.