View Full Version : Dual float solenoid controller question.

09/15/2014, 01:43 PM
Hi, this might be complicated and unclear, but I'll do my best to make it clear:

I am on a well and have high CO2. I don't remember the exact ppm, but it is very high. I have a BRS unit, but recently changed to your membrane and DI resin. I also recently added your two DI stages that contain anion exchange resin alone (that I will regenerate). Anyhow, because my CO2 is so high, I'm still using up a ton of resin. I didn't want to, but now I think I need to setup a sparging system.

Okay, two part question:


I know you have a DIY (PVC pipe based) that will work on your website for sparging, but I want to do it before the RO membrane (after the sediment filters) and have something more automated. He is what I am thinking:

well -> sediment / carbon stages -> (solenoid) -> BRUTE -> Aquatec 8800 -> RO membrane

I was thinking of setting up a sparging container using a Brute trash can and your dual float solenoid controller (air pump with aristone would run 24/7). That would keep the water level in the Brute regulated between the two floats. I already have an Aquatec 8800, so I can provide the needed PSI to the RO membrane. My house PSI is 40-50, so I should be fine to get water into the Brute with house pressure alone.

Another possibility would be to do this before any of the sediment / carbon stages, but that might eventually clog the solenoid, right?

I don't want to sparge after RO because my system is a bit complex and after the RO it goes to a pressure tank for drinking (and the pressure tanks act as a reservoir / pressure to push the RO through the DI stages).


I also want to use your solenoid controller kit to regulate my DI water (so I can have ATO pull right from another Brute). This would look like:

RO membrane -> pressure tank ---> (solenoid) -> DI stages -> BRUTE (topoff and makeup water)

I think this is a bit more conventional use of the solenoid kit, so this should work fine, right?


Sorry for the long post, and I know my system is over-complicated, but I want to this automate as much as possible... and I realized that even adding extra anion resin wasn't an ideal way to deal with CO2.


09/16/2014, 03:04 PM
If you sparge the tap water instead of the RO water, you will need 3-4 times as much water in tap water barrels as you will make after the RO. Give treating the RO another chance.

A well-placed check valve on the RO line after a tee and just before the pressure tank will isolate the drinking water/pressure tank from the DI production. When the sparger doesn't need water, the pressure tank will fill and stay filled. Run the RO into a barrel and de-gas it. Use the 8800 pump to move the degassed RO water through the DI stages at a controllable rate. There's really no need to steal pressurized drinking water from the tank to fill the fish water barrel. It makes for uneven flows through the DIs (first, too fast, then too slow) and then you don't have drinking water when you want it.

If you can consider this option, we might come up with a different plan for your Question #2.

Scott at SpectraPure

09/16/2014, 07:07 PM
Thanks, Scott.

I'm not totally opposed to T'ing off before the pressure tank, but...

I just bought one of your 99% membranes (not installed yet) and without a booster I sometimes get as low as 40 psi (with my well, my pressure varies between 40 and 50 psi). I really wanted to use the booster before the RO membrane to get the TDS as low as possible. Having a 99% rejection membrane with sub-optimal pressure seems like a waste (of DI resin).

And if it changes your opinion, my RO pressure tank is 44 gal and I never use more than 30-ish at a time for the aquarium. I have a litermeter for AWC so I don't really ever need large water changes. Basically, I don't think I'll need to "steal" water from my drinking supply (but that is a concern because we have high arsenic in our well and my wife would be mad if we didn't have water to drink or cook with).

Your point about uneven flow through the DI is a good one. What is the optimal PSI or flow rate for that? Assuming I kept the 8800 before the membrane, are there any pumps that are optimal for putting water through DI resin?

Above all, I want the sparging to be automated (leaving the air pump running 24/7 is fine with me). And I'd like it automated in terms of filling my RODI bin. Other than that, you are the expert, so if you think it's better to treat after the RO, I'm open to it.

09/16/2014, 11:41 PM
I'll reduce my concerns to two:

1. You still need 3-4x tap water to be sparged for 1x product water.

2. The booster pump sucking out of a tap water barrel (0 psi) may not make it to 60 psi. Better to have the booster pump between tap and membrane for as much working pressure as possible - you'll probably make 80 psi. If the sump isn't too far away and you don't need much head, a cheap powerhead can move the water out of the sparged RO barrel and through the DIs.

The DI carts seem to like the flow rates of a 90 to 180 GPD system, so 250 to 400 ml/min. works well.

And back to your original #2 question: yes, the LLC-S would do what you want to do.


09/17/2014, 09:27 AM
Thanks again, Scott. Good points.

Okay, does SpectraPure sell a pump that would be ideal for taking non-pressurized RO water through DI canisters? At most, it'll be 4' of head. As you'll see below, I want the pump to be controlled by high/low floats. Is a small powerhead like you suggested more appropriate than another 8800 (I know the powerhead would be cheaper but I also want this system to be robust and once setup require little attention)?

I'll plan a LLC-S to control filling of a brute with trashcan. Water level will be regulated by the dual floats using the solenoid to turn on/off RO water supply. I will t-off before the RO pressure tank.

So for this I'll need: LLC-SVC-2FLT-4-10

Then for the DI holding tank, I will need high/low floats and a pump that can be turned on/off via the floats. Can you recommend something for this? Do you sell a switchable plug that could turn on/off a powerhead using dual floats? I've seen these elsewhere but didn't know if you sell them?

Thanks for all your help and suggestions!

09/17/2014, 10:16 AM
Here's a kit with the smaller, cheaper 6800 pump (BPLF):

BPLF-SVC-093-2EF , minus the solenoid. It's out of stock at the moment.

At this point, let's take this to PM or a phone call,


09/17/2014, 10:40 AM
Okay, I'll PM you.

Thanks for the help!

09/22/2014, 11:47 AM
Did you call sales and order the part?


10/10/2014, 10:13 AM
Did you call sales and order the part?


I tried... I wanted to talk to Scott and kept missing him. I left my number twice and didn't hear back. I also talked to someone in sales, but I kept getting put on hold and got tired of waiting.

In the end, I decided to go with an Apex-DIY solution that I think will work out well.

I still love you guys, but while your answers online here have always been supremely helpful, I found it hard to get answers over the phone.

10/10/2014, 11:11 AM

Sorry that you weren't able to get a hold of Scott. I typically listen to all of the technical support emails. I do not remember getting a message from you on the support voicemail box. Either way we appreciate the praise on us rocking.

If you need any technical help you can contact me

[email protected]apure.com
480-894-5437 ext 2


10/10/2014, 11:38 AM
Sorry that you weren't able to get a hold of Scott. I typically listen to all of the technical support emails. I do not remember getting a message from you on the support voicemail box.

I left two messages for Scott with a live person (not on your answering machine and didn't email either -- in retrospect, I should have emailed).

When I called the third time, whoever I was talking to was helpful, but I didn't understand how the BPLF-SVC-093-2EF product worked in terms of ordering, and it seemed like he had to keep taking other calls. I waited through three cycles of asking my question and then holding and then I gave up on the 4th time of being on hold because I still didn't have the answer.

Anyhow... I still might want to get the BPLF-SVC-093-2EF product someday (not immediately, I want to try to do this with Apex, but I don't love the idea of everything being automated using a single controller/system). I'm still confused on exactly what BPHF-SVC-093-2EF is... It's not in stock on the website, but it actually seems to be made up of two different products that are in stock? Is that right?

10/10/2014, 12:22 PM

I am very sorry that your call was not returned. If you want to talk about it again at anytime please let me know. I will be more than happy to help you out.