Automating RO/DI with redundancy

[ReefDreamz]

I'm in the process of planning a new 200 gallon tank. I'm in the research stage and trying to decide on equipment and what components I need. I think I've decided to go with a Profilux 4. I'm trying to plan out my RO/DI system and need some help. So far I have figured out I want a 7 stage 200 GPD RO/DI with an auto shut off valve, 8800 booster pump, pressure switch, and 800 mL/min auto flush flow restrictor. I'm going to use the RO/DI container in my saltwater mixing station but also as my ATO reservoir.

Out of the box, the RO/DI is controlled only by a float valve placed in the RO container that triggers the auto shut off valve and the booster pump pressure switch to close shutting the flow of water off and the booster pump off respectively. I'm trying to figure out what else I need to add redundancy and make use of the Profilux. I have seen some use an Xp Aqua Flood Guardian plugged into the 6E-PAB and just control when the flood guardian has power or not to limit the amount of RO water that can be made for a given time period. But I wonder if the same or a better system can be made using the Profilux float switches and optical sensors? To my knowledge Profilux doesn't make a solenoid valve.

So how are people automating their Profilux controlled RO/DI systems and what components are required?

 

[Lasse]

Is the shout off valve normally closed? (i.e. no current - closed) ?

You can with a fix use the nainternal float valve to control a level function in P4 and the booster pump can be switched on and off by a powerbar. You can also use a second (profilux level indicator) as an emergency shout down if the internal switch do not work.

Sincerely Lasse

 

[csund]

You can use any solenoid valve you want. 110, 12, 24… use a switch channel with power supply if DC. Some solenoid valves need a pressure differential to work properly so pay attention to that.

 

[ReefDreamz]

Ok thank you! So I could use one of these solenoids and 2 of these level sensors to control my RO/DI with a P4, correct? Put one sensor at the high water level but just below the mechanical float valve and one sensor at the low water level. Program the P4 to open the solenoid when the low sensor is dry and close the solenoid when the high sensor is wet. Use the mechanical float switch as a backup if the high sensor or the solenoid fails. Sound right?

 

[csund]

You could. I would probably look at using a plastic solenoid valve that doesn’t have metal contacting water. It may not be a big deal with RODI but I don’t know for sure.

 

[ReefDreamz]

You could. I would probably look at using a plastic solenoid valve that doesn’t have metal contacting water. It may not be a big deal with RODI but I don’t know for sure.

Do you have a recommendation or a source for plastic solenoid valves with 1/4 fittings?