RO and auto-topoff question

C

chrissreef

Would it negatively impact the RO/DI unit/membranes by having the float valve directly in the sump (constant on/off) or would it be better to have a resevoir to which I would take water from every day to top off with (i.e. the unit would run continously to replenish the 5 gallons I scoop out)

Thanks!
 
As long as the float valve is salt water safe I don't see why you couldn't. Just make sure you have a system to shut it off if it gets stuck in the on position. Not sure how that would be worked out but I know some people on here have their RO units feed their sump.
 
yeah you need to have the shut off valve on your ro unit...or it will just push the water back as trash water
 
Not to mention if your valve/switch gets stuck on, youll keep pumping H2O into the tank. Do a holding tank of no more than 10G and just refill it.
 
I thought I heard somewhere, and let me preface first I have never owned an RO unit... but the first bit of water out of them is full of TDS creep??? So if you plumbed your RO unit directly to your return section, all you would really get is TDS creep in your system.

Sounds logical to me.

I think you should always dump the first half a gallon or more before using the water from the RO unit. ???
 
@chrissreef wrote:
Would it negatively impact the RO/DI unit/membranes by having the float valve directly in the sump said:
No, but I'd think twice about it. I've heard stories of RO units being connected directly to the sumps that have stuck open. You would end up with a big mess on the floor plus a huge drop in salinity.

Here is how I add RO to my 220g. I have an auto top-off float valve in my sump that is fed by a small MaxiJet from an 18g tall tank. I keep the top-off tank between 5-10 gallons. If the valve ever stuck open my system would be able to handle 5-10 gallons of RO.

Mark
Click to expand...
 
somewhere I read you don't want to cycle the RO/DI unit more then needed (avoiding the short but many on/off cycles) I don't know if this had someting to do with the membrane life or the tds reading. I'll see if I can find it.
 
thanks =) I guess I'll have to settle for a reservoir of water next to the display =(

(although I've heard of using a float switch as a backup for the float valve)

TDS creep - I've heard of it but always ignored it. I’ll look into it but I guess I've always figured carbon+phosban+3ft skimmer = lazy reefer =P
 
Please read this before you proceed:

http://www.melevsreef.com/rodi_recipe_for_disaster.html
 
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