ro/di modification

[mkzimms]

so i just picked up an ro/di unit for myself online. having my own really beats driving 30 miles to my dads house to mooch off his, especially since im starting up a new tank (60 gallon total volume) and will need larger amounts of water to fill and keep topped off.
i have been very happy so far with the unit i got and have read good things online about it. its a 5 stage ro/di with a digital dual channel TDS. the one negative comment i have about it is the DI units are mounted horizontal from the factory. if you didn't know, when the water is moving through the di units it will channel and endup not passing through the media if it is horizontal. since i do not have a dedicated place to hook this baby up i needed a more secure yet mobile way to mount it according to my ever changing needs. so heres what i came up with
ORIGINAL SETUP - sure it was cool looking and very compact but not very sturdy with the DI units just clipped on and they were horizontal...

NEW SETUP - its now mounted to a large piece of wood and everything is cabletied down and the main unit is held with bolts. i can easily pick up the whole thing and move it when necessary. its a little bigger now, but way more convenient. i mounted the di units vertically and they now flow from the bottom of the canister to the top and then into the next unit so every bit of water touches the medium.

btw: if you were wondering why the hoses are running out the windows its because i feeding the unit off the garden hose. im actually getting really good flow from it and we have good water to begin with in my area. im getting 50-60 TDS in and 0 out. my filters should last a long time because of that. at my dads house hes getting 250 in and 0 out. i would expect a much shorter filter life from his.

 

[waterworld]

Why did you mount the DI units to run the flow from bottom up? Would this not allow the media to settle and pack into the bottom? Would upflow keep the media loose to contribute to channeling? I would have guessed to mount with flow from top down so the water pressure would push media to the bottom and forcing water to pass through the media.
I am currently in the market for a Ro/DI unit and certainly appreciate your thoughts. Also not to divert the thread but a quick question on a RO/DI unit. Does the drain from the unit need to run downhill or can I route the drain to a higher location? Example, Unit in the basement and run the drain outside to my garden. Total rise of about 4 feet.
Might as well have the discharged water put to use!
Thanks
WW

 

[mkzimms]

when the flow comes from the bottom up it will cause a fluidized bed which will keep the media in the canister even and the the flow distributed evenly. when the water flows top down it will compress the media which will form channels and the water will go to the areas of least resistance bypassing the media when possible. the pricipal would be the same as using a fluidized bed filter where the water moves evenly dispersed from the bottom up to ensure all the water comes in contact with the medium.
i dont know if you could put the drain higher, ill give it a try later for you and let you know the results. i would assume if you had good enough water pressure you could. i have 60psi from my garden hose. the drain water may not be so good for the plants should since it is lacking most of the nutrients and minerals they would benefit from. someone who knows a little more about plant physiology would have to chime in on this.