RO Water

[Petalas82]

Question, My buddy gave me a nice RO system and I am getting 30-33 TDS. Is that ok for my salt water aquarium. I have been getting my water from the grocery store, they clam it RODI water. I have never tested it and my tank has been fine, I am going to test it tomorrow to really see. But I would like to use this RO I got but its saying 30-33 TDS. Will that work for my tank.


Thanks

 

[chbix]

I think you should be getting less than that closer to zero.

What is your water prior to?
You may need to change the filters if its used.

 

[CorallineAlgae]

It's not ideal and you can probably use it. You may be able to get it running better. Can you tell me the TDS of your unfiltered tap water, how many GPD your membrane is rated for (50 or 75 or ?) and what the pressure is at the membrane from the pressure gauge? All of these things can affect the TDS coming out of the filter. The filter may be working fine or not depending on these factors.

 

[Petalas82]

TDS from unfiltered is 435. There is no pressure gauge on it so I have no idea. Its a 2 stage system. It has a 1 Micron Sediment Filter, Carbon Block Filter. My buddy said that the GPD depends on how bad the water is and how long it takes to treat it.

 

[Gregcoyote]

It also has a reverse osmosis cartridge doesn't it? A properly working 3 stage filter like this should make water under 30-40 TDS. Adding a DI canister will push it to zero and that's ideally where you want to be.

 

[Gregcoyote]

TDS from unfiltered is 435. There is no pressure gauge on it so I have no idea. Its a 2 stage system. It has a 1 Micron Sediment Filter, Carbon Block Filter. My buddy said that the GPD depends on how bad the water is and how long it takes to treat it.

Your friend is mistaken, GPD is a function of the supply water pressure and the flow rate your RO membrane is rated at. The RO filter is the bottle neck.

 

[Petalas82]

Here are some pics of what I have. Sorry for them being upside down, I tried to fix it but there still were upside down.

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[CorallineAlgae]

TDS from unfiltered is 435. There is no pressure gauge on it so I have no idea. Its a 2 stage system. It has a 1 Micron Sediment Filter, Carbon Block Filter. My buddy said that the GPD depends on how bad the water is and how long it takes to treat it.

Aa an example if your membrane had a 94% rejection rate and was running under it's operating pressure you could expect a TDS level around 26, give or take. Different GPD membranes have different rejection rates and work better depending on pressure. If the pre-filters are old it could allow chlorine to lower the rejection or clog the membrane. An easy thing to do would be to get a fresh set of filters and maybe a new membrane. You could find out what GPD unit you have by looking at the numbers on your flow restrictor that goes to the discharge (waste) line. They always match the membrane (a google search can tell you what it matches).

If you want to use the water then you should. You're getting way better water from the RO than the tap!

 

[Petalas82]

I just recheck it and now I am down to 20. They are new 1 Micron Sediment Filter, Carbon Block. But the membrane is not new. My biggest concern is doing damage to my tank. I dont want to kill anything. Thanks so much

 

[CorallineAlgae]

I just recheck it and now I am down to 20. They are new 1 Micron Sediment Filter, Carbon Block. But the membrane is not new. My biggest concern is doing damage to my tank. I dont want to kill anything. Thanks so much

You won't kill anything at all even if your TDS are higher than 20. If it's between 20 and 35 with the high amount of TDS from your tap it's right where it should be for normal RO. Membranes reject a percentage of incoming TDS. Your tank will be a-ok.