RO filter output TDS increasing

project5k

Reef enthusiast
so i've been measuring the tds of my ro water the last few days, and i'm concerned... yesterday i was getting 15, and today i'm getting 34. now over night i did turn off the supply to the filter, cause of some other plumbing issues... so i'm hoping that the water that was inside the filter overnight picked up something, but if this continues what do i do?

is my membrane bad, is my DI media bad, whats going on here??? also, when the ro tank is full, and the float valve cuts off the flow, if i leave the supply on, then there is still water comming out the "drain" line... mine does have the auto off valve, and i wanna say i remember reading something about them somewhere else, but i cant remember right now... anyway... could that be causing the problem? is that valve something that i can rebuild myself? i have orings of all different sizes...

oh, and i guess it might be a good idea to tell yall what filter i have, its a 0tds 7 stage unit from pure water club, theres the 3 big canisters, then the membrane and then 3 di stages....1 x150G 0ppm Reverse Osmosis+2DI Aquarium Water Filter#ROH-6BB-150

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If you have water coming out the waste line when the float valve is in the off position, your auto shut off is not closing all the way. It's that small white box in the front with the 4 lines going into it. Take the 4 screws off and you will see 2 rubber "flap" gaskets. Make sure nothing is preventing them from closing all the way. They do go bad too. I've had to replace mine a few yrs ago.
If it's not closing all the way, water can route itself around the filters and can cause the higher TDS in the output water.
 
ok, i took the little auto off valve apart, all there was inside there was a couple little clear rubbery diaframs... i didnt find any holes in either one, did notice that one was a little larger in diameter than the other... well, the piston area anyway...

so, i didnt find any trash, or anything in there, and its still runing water out the drain line when the ro line is cut off with a float valve....

but at least now i understand how the valve works... the back pressure from the ro line pushes the larger piston'd diafram up and that should in theory seal off the water comming up from the carbon and stuff canisters, and stops it before it goes into the membrane... then when the float valve opens, that back pressure is released, opening the supply to the membrane, and it all starts moving again..

still didnt fix it tho... :( i sent an email to pure water club, but i'm not holding my breath...

Ideas?
 
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Buy a new valve. :) I had to replace mine so I guess it's not all that uncommon they go bad. I think it cost around $6.
 
ok, well at least its not the membrane... i'll order a new valve... wonder if i can slip a permeate pump in on the order without getting yelled at... hmmmm
 
so, no permeate pump for now, but i did send pure water club an email asking about the auto shut off valve, and if that was what they thought would cause the problem, just figured its free info, right?? after a couple emails back and forth over the last couple days, they have sent me an email saying that they will send me a new auto shut off valve, and a new check valve, and no request for payment...

thats what i call awesome customer service, now, i just gotta wait till it gets here...
 
This may be a dumb question but im new to saltwater so bare with me i have been reading about the RO systems to keep pristene water and im thinking about buying one like shown in this thread, the question is if you use RO filtered water do you still need to add water conditioner ?? or do you not have to use it if using RO filtered water??.
Kevin
 
im starting a new 90 gallon tank buy one now for the initial setup or wait until the first water change??? i already bought a bottle of conditioner should i use it first or get rid of it and start wit RO filter
 
is their any special test to the RO/DI water that comes out the unit to make sure its working right before you dump the water to your tank??
 
Yep, you will need a TDS meter if you are going to use an RODI unit. You can get them on Ebay for $10 to $20. No matter where you buy one from, be sure to buy some calibration fluid. You can also get that on Ebay for around $4.
 
yea, thats what i did, i wouldnt use the water conditioner at all, i'd find a friend that has a freshwater tank and give it to them.....

I made the mistake when i started my 75 and it was nothing but a royal pain, uncontrollable brown algae and all sorts of gunk... if you can, start the tank with good rodi water... and like above, get a 15 buck digital tds meter, and cal fluid...
 
OK Biff, im going to order the TDS meter and calibrating solution, the solution is sold by small packs for $1.99 how many will i need ? how does it work? and how often to calibrate?? thanks Kevin
 
You just need one. It should come with a little dropper or scoop thing. The calibration fluid will say which number it needs to be adjusted to -- buy the calibration fluid for 1.026 or something near what we want the salinity in our tanks to be.

Then you put some of the fluid on the refractometer. The refractometer will have a tiny screw on the top or bottom. Turning that screw in either direction will adjust the reading up or down. So you simply need to turn the screw until the reading the refractometer is giving you for the calibration fluid matches what the number the calibration fluid bottle says it should be.
 
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