solonoid plumging on RO/DI for ATO?

[inetmug]

Hi all,

I have a captive purity RO/DI system that I bought years ago. New filters, its all ready to go, TDS = 0.

I have been using this unit for years making water into Brutes, using the faucet hose adapter. I just connect it, and start making water.

I now want to connect this to an ATO setup, the set up will have a kent mechanical as well as electric solenoid/float secondary system for safety. I also inherited a spectrapure system that seems to have a pressure solenoid plumbed inline and on the outbound side of the waste water. I talked to someone in tech support and they told me I needed a 4 port solenoid to sense product line pressure, which would open the waste line, but I have yet to see what he was talking about. The kent float switch case with a three port solenoid.

My understanding is I need to plumb this up as a normal RO system for drinking water has the accumulator tank, and without one, you need to do this so waster water does not continue to pass the membrane when the float switch cuts the product off. I get by with my core system because I control the feed to the input via the faucet.

Can someone tell me or point me to a source of information or a simple diagram of the set up? I am not exactly sure where the solenoid needs to be placed, and if I need one or two.

Thanks in advance.

[FranktheTankTx]

You'll need to ensure that the valve is in line from the output to the solenoid or you risk failure at the inlet of the outgoing line to the incoming line which can cause flooding &/or electrical issues at the front of the connection where the outgoing connects to the incoming coming from the valve fed from the solenoid to the wall.

[inetmug]

I am talking about the pressure solenoid setup on the RO/DI unit itself. The captive purity has no pressure solenoids on it at the moment as I simply controlled things manually via the faucet pressure. The captive purity will continue be used to create water for water changes (but with a float switch in the brute), and to feed the ATO as well. So I will no longer be manually controlling it via the faucet. I am planning on selling the spectrapure unit as it will no longer be needed.

As an example, the inherited spectrapure has two pressure solenoids. The first is a three port that is connected to the second stage, and connects into the membrane, and the a one port version on the waster water output. The captive purity membrane canister is very different from the spectrapure setup.

For the ATO, the primary RO/DI product control will be a mechanical kent float valve. There will be electronic solenoids inline prior to that final valve that will be connected to electronic float switches. This is the backup to the ATO system as I do not have enough space for an external RO/DI tank with pumps etc.

The pressure solenoid that came with the kent float switch is a three port, and the instructions referenced using it with an accumulator tank only.

So what I am asking is how and or what pressure solenoids need to be added to the captive purity system to make it work right. The answer may be "none, one, or two". It is possible that I just need a check valve on the inbound or outbound side of the DI canister. I have found many diagrams showing the accumulator/pressure tank, including a 4 port pressure solenoid, but no drawings without a pressure tank. I do not need the tank, and this is also not feeding my drinking water. The ATO will not take more than 2G/day.

[inetmug]

There is another thread I found, which states that not using a reservoir can lead to low/short use of the RO/DI daily. It makes sense. Run the reservoir down, and then fill it. However, you will still get the kaka beginning water in the reservoir at the beginning of the fill cycle, so I am not sure it matters in the end, would just have to check. The good thing is you would get it dispersed over the total volume. The same holds for the accumulator tank if in use.

But, I would also imagine that using a low output RODI would allow the float switch to cycle several times/day. If it cycled enough, it might actually dispel LESS kaka water than the reservoir method. You would just need to test it.

Ideally, you use a TDS meter on a electronic solenoid switch valve, discarding the product until it reads zero. Then the solenoid allows the zero TDS product into the tank, or reservoir. Wonder if they make such a thing? But, you will need to either set an alarm on the sump/reservoir in the event the TDS reading never gets to zero.

Another option, T the product line to an solenoid attached to a timer. Put that line into the waste water stream. This would allow the RO/DI to cycle periodically during the day. With an electronic timer, you could get many on/off cycles of a programmable duration. Some people put their ATO on a timer anyway, so it can only run when they are home for example. You could use this system to run the RO/DI for a period of time, before you do the sump or reservoir fill. Again, you need to monitor the TDS, maybe elongating the time it runs as your filters start to give way.

OVERTHINKING THIS..... maybe, maybe not. With my old 55G, I just made a brute fill up, and just drew out water via a valve. I can tell you the TDS started at zero in that tank, and finished at about 10-12 as an average. Why? Dust, contaminates, CO, etc. My take is the same thing will happen to a reservoir ATO system IMO.

Nothing is perfect other than the system I mention above, you need to clear the RO/DI unit on each and every use if you REALLY want it clean. And you can not store it for long and maintain zero TDS.

[FranktheTankTx]

Yes - I had an ATO filled with 0 TDS from RO/DI. But in a couple of days the reservoir tested for TDS.

I accepted the fact that it is what it is.