Ro-Di filter, are they all the same?

[reefmaster]

Hey, im looking to buy this Ro Di filter http://orangecounty.craigslist.org/hsh/305251626.html
Its not kent or any other popular brand im sure but will it do the same job as the ones that are advertised on aquarium websites and such?

thanks

 

[Steven Pro]

I don't know anyhting about the unit you linked to, but I cna say that not all RO units are alike. There is a world of difference in the quality of the components used.

 

[Devilishturtles]

It's impossible to see the brand name on that filter. It looks like it's in good shape though, and also has a DI resin which is nice.

Steven is right, there IS a difference depending on which one you order.

 

[melosu58]

I don't know anyhting about the unit you linked to, but I cna say that not all RO units are alike. There is a world of difference in the quality of the components used.

I totally agree.

 

[lando]

The price is good, however, you could very well end up spending more then that on new media and filter inserts for it. I would suggest replacing them all as you o not know the lenght of service or quality of source water it has filtered. While I think an RO/DI is one of the best investments you can get for your tank, make sure you get a decent quality one. Persoanlly, I like www.thefilterguys.biz

 

[Ziggy953]

Excellent points..I would also suggest checking on Ebay!

 

[ellisz]

I have been using a Aquasafe unit that I bought on Ebay a few years ago. To me, the unit appears to have done great and was a great price.

Lately I read threads on other boards where these Ebay units are dissed on. My argument here is as long as the TDS readings are 0-1 when it runs through the unit, are we not doing everything that can be done? I know the internals might be cheaper in some units but I don't really know the brand on my membrane or carbon filters. It seems to doing working though.

From what I have gathered, if your TDS of your tap water is low to begin with, you might be OK with a cheaper unit to some extent. With the cheaper internals, you might be making the DI chamber work harder and cause it to be depleted quicker. SOme of the Ebay units are being called cheap for there canisters and the fact that they have horizontal DI chambers. I can see the benefit of clear canisters and a vertical DI chamber but as long as the TDS is good at the end is something not being filtered?

Am I wrong in saying the above?

 

[Devilishturtles]

I use the RO/DI unit off ebay and don't have an problems with it. I think it's a great unit for the price. But, a more expensive unit might "perform" better (ie: quicker, perhaps less TDS overall, more efficient in waste water output, etc) I dunno.

However, I've seen small units for sale that are priced extrememly low, that I just wouldn't buy for my tank. I think any 5 stage RO/DI unit or similar would be great for our tanks.

 

[Steven Pro]

Any RO/DI unit can produce water that has a 0 reading for TDS. The difference is how much the cheaper units are going to cost you in the long run in replacement DI cartridges.

 

[ellisz]

Any RO/DI unit can produce water that has a 0 reading for TDS. The difference is how much the cheaper units are going to cost you in the long run in replacement DI cartridges.

That is what I figured. Its just that some people really bad mouth these Ebay units. I have replaced my DI unit 3 times in about 2.5 yrs. Sometimes just because it seemed like it had been awhile. My TDS readings were still below 5.

I am going to add a add on DI chamber with re-fillable media after my current one is exhausted but I have been extremely happy with mine. There have been a few fights on RC on this issue though ...

 

[Steven Pro]

Any RO/DI unit can produce water that has a 0 reading for TDS. The difference is how much the cheaper units are going to cost you in the long run in replacement DI cartridges.

That is what I figured. Its just that some people really bad mouth these Ebay units. I have replaced my DI unit 3 times in about 2.5 yrs. Sometimes just because it seemed like it had been awhile. My TDS readings were still below 5.

When was the last time your TDS meter was calibrated? Three changes in 2.5 years is very little and makes me suspicious of your reading.

 

[ellisz]

Well, it was calibrated when I bought it and that was the last time. I don't have any of the calibration solution on hand though. Maybe I will have a friend try theirs out and compare.

 

[ellisz]

Well, with the new 180, I changed out all my white canister to clear canisters and added a dual DI system to replace my single. I also put in a new dual TDS meter.

Weird thing is that my incoming TDS is 205 and the TDS before the DI stage is 0. This is with a 3 yr old membrane and carbon/sediment filters that are about 3 months old. I tested the after DI water with my old TDS meter and it came up as 1.

I had also tested my TDS meter with a friends TDS meter on his RO/DI unit. It checked out on his system too.

 

[roka64]

Can't you calibrate them with distilled water? I'll have to look at my instructions to double check.

 

[seaham358]

Any RO/DI unit can produce water that has a 0 reading for TDS. The difference is how much the cheaper units are going to cost you in the long run in replacement DI cartridges.

That is what I figured. Its just that some people really bad mouth these Ebay units. I have replaced my DI unit 3 times in about 2.5 yrs. Sometimes just because it seemed like it had been awhile. My TDS readings were still below 5.

When was the last time your TDS meter was calibrated? Three changes in 2.5 years is very little and makes me suspicious of your reading.

I can tell you that I have had resin last over a year with only showing a 2-3 on the TDS meter (I have 2 meters). I am running dual DI's and a booster pump so this helps it last longer. Before the booster I would get less then 3 months from my resin.
My buddy also gets about a year from his resin w/a booster pump.

 

[Phyl]

I've been running the same FilterDirect (off of ebay) unit for 3 years without changing a thing. It is still running 0-1 TDS. I was quite concerned that it would go so long and still produce zero TDS water, so I've validated it against others and have come up with a very small margin of error.

Might be time to dig up some calibration fluid just to triple check it, but I'm not having any algae issues either so I have a great deal of faith in the numbers!