RODI Ideas

MSB123 · Dec 4, 2018

I am trying to set up a RODI ATO.
My plan is as follows.
Use the BRS 5 stage RODI system.
https://www.bulkreefsupply.com/5-stage-premium-ro-di-system-bulk-reef-supply.html
Connect the return line from the RODI to an apex solenoid valve.
https://www.bulkreefsupply.com/sv-1-solenoid-valve-neptune-systems.html
Connects that to another piece of line which goes into my sump.
Connect a BOB to my apex
https://www.bulkreefsupply.com/neptune-systems-i-o-breakout-box.html
Connect the BOB to 2 float switches (For reliability, both would have to be up or down to turn on/off the water)
I dont know which switches would be best. Any ideas?
Set up the Solenoid so that it is opened when boths switches are open. Have it close when one or both switches are closed (so if one fails it will still shut off)

I also want to set up some sort of failsafe so that if it is open for more then say 5 minutes(or a preset amount of time where the RODI should of filled the tank up), it will shut off.
Is this a good idea? Has anyone else done something similar?

KMSReefer · Dec 4, 2018

I have my rodi set up with an ato system. I use two solenoids, one to turn the unit on and off and the other to flush the membrane. Mine tops off a reservoir under my tank with a mechanical float valve and I have the neptune auto top off topping my sump up from the reservoir. I have an extra optical sensor above the mechanical float that is plugged in to the auto top off and stops the rodi if the mechanical float sticks. I also have the leak detector for extra redundancy. Mine is set up to turn on for a few hours twice a week to refill the reservoir.

MSB123 · Dec 4, 2018

KMSReefer said:
I have my rodi set up with an ato system. I use two solenoids, one to turn the unit on and off and the other to flush the membrane. Mine tops off a reservoir under my tank with a mechanical float valve and I have the neptune auto top off topping my sump up from the reservoir. I have an extra optical sensor above the mechanical float that is plugged in to the auto top off and stops the rodi if the mechanical float sticks. I also have the leak detector for extra redundancy. Mine is set up to turn on for a few hours twice a week to refill the reservoir.

I think that the leak detector is a good idea.

KMSReefer · Dec 4, 2018

I prefer to have the resevoir under the tank because my resin seems to last longer when the rodi runs for longer time periods than if it is used to top the tank off directly.

MSB123 · Dec 4, 2018

I dont mind about resin. How much does yours cost?

chefjpaul · Dec 4, 2018

Here is my set up.

Ato, which is about 60 feet away in fish closet, lines run through my crown molding.

Into the 10 gallon reservoir, right side under tank.

This involves 5 float switches. (6 total for both tanks).

High / low for the reservoir.
I also keep a high / low in the tank sump area.
Along with the ATO floats.

This all runs through my GHL, with flush for RODI, with volume of water produced. The RODI turns on when the reservoir gets down to 2 gallons left. Stops at 9.5 gallons.

MSB123 · Dec 4, 2018

Thanks! I really perfer to have it go directly into the sump, just because I don’t have much room for an ATO container

cromag27 · Dec 4, 2018

that setup will dump the membrane tds creep right into your sump. but if you’re ok with this, then it should work. i know several people who do this, despite its inefficiencies.

MSB123 · Dec 4, 2018

cromag27 said:
that setup will dump the membrane tds creep right into your sump. but if you’re ok with this, then it should work. i know several people who do this, despite its inefficiencies.

His setup or mine?
Which TDS creep?

cromag27 · Dec 4, 2018

MSB123 said:
His setup or mine?
Which TDS creep?

both. once an rodi unit shuts off, the remaining water in the membrane housing will experience tds creep. typically you don’t want this high tds water in your tank. the solution is to install a flush valve before the di cartridges so you can flush the tds creep before you start collecting product water. some people don’t do this and they’re ok with the tds creep in their tank. might not be a huge deal if you make enough water, but it will still deplete your di cartridges faster than if you flushed.

MSB123 · Dec 4, 2018

cromag27 said:
both. once an rodi unit shuts off, the remaining water in the membrane housing will experience tds creep. typically you don’t want this high tds water in your tank. the solution is to install a flush valve before the di cartridges so you can flush the tds creep before you start collecting product water. some people don’t do this and they’re ok with the tds creep in their tank. might not be a huge deal if you make enough water, but it will still deplete your di cartridges faster than if you flushed.

How would I do that so that it is automated with the apex?
Is it even possible?

cromag27 · Dec 4, 2018

MSB123 said:
How would I do that so that it is automated with the apex?
Is it even possible?

not with an apex. you would need a manual flush kit. but like i said, a lot of reefers don’t bother and they’re fine with replacing the di cartridges more often than necessary. it also depends on how often the rodi would engage and how much water you’re making at a time.

https://spectrapure.com/RO-RODI/ADD-ONS/Flush-Valve-Kit-w-1-4in-fittings

MSB123 · Dec 4, 2018

cromag27 said:
not with an apex. you would need a manual flush kit. but like i said, a lot of reefers don’t bother and they’re fine with replacing the di cartridges more often than necessary. it also depends on how often the rodi would engage and how much water you’re making at a time.

https://spectrapure.com/RO-RODI/ADD-ONS/Flush-Valve-Kit-w-1-4in-fittings

Could i use that flush valve kit but replace the black valve with a solenoid?

cromag27 · Dec 4, 2018

MSB123 said:
Could i use that flush valve kit but replace the black valve with a solenoid?

you would need to program it to open and stay open for x minutes. i’m not sure how you would do that since the rodi unit may kick on at different intervals, depending on your evaporation rate.

MSB123 · Dec 4, 2018

I would program it so that when the low line float switch opens, the solenoid on the flush line would open, and then after a pre set amount of time, it would close and the fill solenoid would open.

cromag27 · Dec 4, 2018

MSB123 said:
I would program it so that when the low line float switch opens, the solenoid on the flush line would open, and then after a pre set amount of time, it would close and the fill solenoid would open.

sounds like that could work. i’m not familiar with programming solenoids though. you would just need to test the outgoing water to determine how long it needs to run to remove the tds creep water. it usually doesn’t take too long.

MSB123 · Dec 4, 2018

cromag27 said:
sounds like that could work. i’m not familiar with programming solenoids though. you would just need to test the outgoing water to determine how long it needs to run to remove the tds creep water. it usually doesn’t take too long.

Yeah. This is going to be more complex then i thought

Turning from a $250 project to a $350 project