Tell me what you think of my plan! Rough Sketch included!

[jherrin215]

Here is my plan for my RO unit, topoff's and PWC's. All comments appreciated. All valves are solenoid controlled and entire system will be controlled by PLC. Only manual valves are for flow adjustment. Thanks in advance!!

Filling RO Tanks

Water will come from RO unit into RO only tank. When float switch on RO only tank closes & switch is set to SALT then valve to RO uint coses. If switch is set to RO then once RO tanks fills and switch closes the RO/Salt tank valve opens and valve to topoff closes and RO unit continues to run and pump in RO tank pumps water into RO/salt tank until float switch in RO/Salt tank closes then RO unit runs until both switches are closed and valve to RO unit closes and valve to topoff opens. Switch stays in RO mode until salt is added and salinity is correct then switch is changed to SALT and will not be changed back until all saltwater is used and emptied by drain installed on bottom of RO/Salt tank.

Topoff

If float switch A in sump opens, turn on pump in RO only tank, close valve to RO/Salt tank, open valve to topoff. Turn on pump in RO only tank until switch closes. Switch must be set to Topoff, and not Water Change.

Water Changes

Switch 1 must be set to SALT, meaning water in RO/Salt tank is saltwater and has been mixed and salinity tested. Switch 2 turned to water change. Press start PB. Open valve from overflow to waste allowing some water to go to waste instead of sump. As level in sump drops float switch B opens turning on pump in RO/Salt tank. At same time the pump turns on, close waste valve, filling back up sump. Once level rises to close switch back run pump for predetermined amount of time the repeat. Do this set amount of times until required amount of water has been changed. Continue to run pump in RO/Salt tank until level in sump closes topoff float switch. Once topoff float switch is closed then turn off pump and manually drain rest of salt from RO/Salt tank and turn switch back to RO. Return pump never powers down and should never run dry. Return pump will be on Backup Power supply.

Rough Sketch

 

[ccCapt]

Looks good. How do you get the RO/Salt to the sump or main tank?

 

[lance]

SO you have an external return pump? What size is it? What ever the rating is , say 800 gph by the time it travles up and out of 2 return jets you have maybe 200 gph if your lucky. This amount of flow does nothing for the main tanks water flow needs , i would use only 1 return jet. You can drill a small hole in the return jet about 3 inches below normal water level to prevent flooding.So added powerheads will be needed for proper water circulation. But everything else looks fine.

 

[jherrin215]

How would that hole prevent flooding?? Also I run 2 maxijet powerheads and use a sea swirl as 1 return for more circulation.

I already have a pump I use for clean saltwater, just forgot to add it in the pic. It's just a small pump.

 

[lance]

If the main tank water level drops below it will stop the siphon.
What size tank is this and whats the GPH rating on those powerheads and the rating on the return pump?

 

[jherrin215]

It's a 125, I think the pump is 800 and not sure on the powerheads, I think they are maxijet 250's?? Does that sound right?? Also if I drill a hole beolw the return level on my return which is a T out of PVC then the water level will already be below the pickup protion stopping the siphon anyway

 

[lance]

In a 125 you want 2 powerheads that give around 1200 GPH each . You have around 800 includeing the return pump . But i never include the return pump as flow for the main tank. If done right then the small amount it adds only helps.

 

[jherrin215]

So do you think it would be better to just have the sea swirl as my full return and do away with the PVC T in the center of the tank, then get 2 larger powerheads for more flow??

 

[lance]

The return is for the sumps needs. Besides if its a mag 5 for example by the time it reaches the out lets its less then half the rated output with one return jet and less with 2 then after it gets dirty less.

If you use 2 outlets use some shutoff valves incase you need to reduce it.Get 2 K4's minimum or 3 k3's. I like to use the rio pump. It has a duckbill tip for dirrection control and flow control knob for flow control plus it doubles as a water change pump.Just get a clear tube and you cna drain and fill and mix the new batch of salt water before change.