High TDS Question New tank

[blackz151]

I finally started to fill my 80 gal deep blue rimless. A friend of mine let me have his seachem 200 gpd ro/di unit. I replaced all the filter both the roe's and the pre and di filters. I flushed it. Ran about 30-40 gal though it 0 tds on product water. Mades about 10-15 gal of ro for my other tanks same thing 0 tds.

Long story short went to go fill my 80. About 1/4 of the way into it I checked the TDS and it was up to about 20 out of now where. Checked the DI media and its fouled up. Started trying to figure out why it went so fast. Out of the RO membranes I'm getting a tds of 140 or so. And the in coming water is only right around 200 at pretty much 50-60 psi.

I hooked the tds meter up to both the waste and product lines. The are almost they same. Ive tried everything. I've pulled the membranes. I tried to reseat them. I took all the pre filters out and put them back in. I tried to flush the ro membranes by pulling the restrictors. I can not get that number to budge. This morning I tried to bypass the auto shut off valves and run water right into the product in on the ro membranes and still nothing. I also tried to bypass one membrane and just one 100GPD and still no change

Does anyone have any clue what the hell is going on. I just don't get it at all I can't get the number to budge at all. It moves around from like 140-120 and thats it. Did these membranes foul out already. Is there anything else I can try?

Thanks for any help in advance

 

[blackz151]

I think it may be the housing for the membranes does any one know of any local place that has them? Or will I need to order online

 

[mrx66699]

The membrane is channeling water and allowing it to bypass actually going threw it ....has to be the way its seeded or a bad membrane

 

[DamonG]

You probably would be better off, just buying new membranes. They sound like they took a dive on you and wiped your di resin as a result. Unfortunately it happens and it's no one's fault. Just a part of the maintence of the hobby.

 

[blackz151]

Thanks guys. I finally got them to come down to about 40PPM after the RO. Which is still high its pretty much what MRX said. The membranes where not sitting right. I think it may have taken the membranes out I tried to flush them got it down to about 30 PPM. Going to get some new DI and get it filled then take care of Ro membranes.

 

[mrx66699]

I think your doing that backwards get the membrane changed then get the new di or your going to burn through the di quickly again

 

[blackz151]

Ok not a problem. I have them all on there way. Thanks again for help!

 

[Buckeye Hydro]

So it sounds like you have two 100 gpd membranes on that system. Seachem membranes are spec'ed at 65 psi, not the more typical 50 psi of Filmtec membranes many are used to. Seachem doesn't provide rejection specs on their membrane, so I suspect the 100 gpd element is around 90%. Given that, your 200 ppm feedwater, and your below spec pressure, I'd expect to see your RO water at something around 20 to 25 ppm.

Maybe your new membranes are a better brand? If your new membranes are Filmtec TW30-1812-100HR's, then I would expect to see your RO water down around 8 to 10 ppm. Which would make your DI resin last 2 to 3 times longer.

Russ