What is a good RO/DI Filter

[quazi]

I have read a couple of people stating "You need to get a good RO/DI filter." OK, what does that really mean? I have a AquaFX barracuda, and it converts 165 TDS water to 0 TDS water. It seems very good to me. I bought it a while back. Now there are lots of less expensive units out there. So, what is the difference?

 

 

 

All "residential" (non-commercial) filters use the same 10 inch size canisters. They can take the same filter inserts. They are connected with "quick connect" type connectors. The internals may be better or worse. Of course you can upgrade components.

 

 

 

Here are a couple of things I think make a good RO/DI filter:

 

 

 

1. Filtec RO membrane. Why go with less than 100 GPD? Just $?

 

2. 1 micron filter (it is nice to have a 5 or 10 micron in front of it, but that may be overkill)

 

3. Carbon cartridge (of course!) - But what kind? There seem to be lots of different kinds - block, Granulated, Chlorine busters, activated catalytic carbon, etc. Does anyone have any real information on what is best?

 

4. DI - It looks like DI is DI. Color changing or not. Is "nuclear" grade DI so much better the "regular" DI media?

 

5. Pressure gage - I am not sure what this really does. This is needed to ensure you are getting the right input pressure to the filter? If the incoming pressure is too low, you need a flow restrictor and/or a booster pump, yes?

 

6. Built in TDS monitor - I think this is a requirement for the good RO/DI unit. Just look at the monitor and you know the health of your unit. This is a must have. It costs ~$30 or so.

 

 

 

I also think having some RO storage is best. I use a float valve and a 45 gallon rubbermaid trash can to store RO water. That means I also had to invest in a auto shut-off valve. This was the best thing I did! Now I have lots of RO and water changes are much easier. Now I need a SW storage, and life will be very simple.

 

 

 

Anyway, please comment on what you think make a "good quality" RO system. It seems to me if the components are good, one is the same as another. Even if you got a "lower quality" filter, you could upgrade it when you change media or add on a canister.

[DEEPBLUE]

Goto www.Aquariumwaterfilters.com, in my opinion, Aquafx ro/di filters are the best and you can make any combination you want just by calling them direct.

 

Eric

[quazi]

DB,

 

 

 

I agree with AquaFX. I have been very pleased with the product and support. But there are much less expensive units out there with similar filer media. Are they as good.

 

 

 

You bring up a very good point. I did not mention service. I have dealt with AquaFX and SpectraPure. Both had outstanding service. Is Buckeye and the Filter Guys as good? How much service do you need on an RO filter?

[Jager]

well the 100gpd units using a 100gpd ro membrane are not the same rejection rate as the 75gpd. long raging fights on RC over this, but if you want more than 75gpd, they daisy chan multiple 75gpd units. the reason for this is that the 75gpd rejects 98% the 100gpd rejects 90-94% so they use up your DI faster.

 

 

the biggest thing these days seems to be this. you can buy whatever RO/DI unit you want crappy or otherwise as long as it takes the standard filters. due to the frequency of filter changes ( i belive its a year or so) after that point you can buy the better filters etc. so if its cost effective bassed on your DI life and your total TDS to use a cheaper unit and use more DI to get a 0 tds, then you "should" get the same effect.

 

that all being said, im paraphrasing and such from RC threads, so dont shoot the messenger :P

[rmoyer001]

I am actually investing in my first. what do you guys think of this model. Its pretty cheap at 145. a LFS around the corner had a barracuda for 270 which i thought was appauling.

 

 

 

 

 

http://www.reeftanksupply.com/index.php?cP...8f9be6f1c717272

[steveoutlaw]

I had and AquaFX and now have a typhoon 3 from airwaterice. I like the Typhoon 3 better and AWI has fantastic customer service as well.

[Jenny]

We have a purely h20 6 stage that removes chlorine and chloramine. We really like it. It comes with a tds which can read tds in and out. It also comes with a pressure gauge which allows you to set it at the most efficient rate.

 

Just to add to what Jager is saying. According to the extensive discussions on reef central about ro/di... the 100gpd ro aren't really ro at all. They are microfilters which is why they don't reject as many disolved solids.

75gpd is optimal apparently which is why many companies making ro/di specifically for aquarium use are no longer offering 100gpd or are phasing them out.

 

I also understand that you could theoretically get a cheaper unit that doesn't have as good of filters and then upgrade them to better ones later. You would have to upgrade faster b/c the cheaper filters are reported to not last as long. Also if you get the cheaper one there is more likelyhood that the whole things leaks more.

 

Having a 5 or 10 micron filter then the 1 micro will overall save the life of your filters. The change rates are only recommendations. Its not like with bulbs when you really should only keep them for a year otherwise they are doing more harm than good.

 

I think having a pressure gauge is also a must have. The RO will make water most efficiently between 50-60 (at least ours will). So you will have less waste if you keep it in that range. Plus you'll have water faster.

 

I agree a tds meter built in is totally worth the money.

 

Jenny

[kingfish]

I haven't used anything else but I'd have to second the airwaterice.com Typhoon III unit with a float shut off switch. It works fine for me. A TDS meter came with the combo. This was a gift for the holidays.