Solenoid for RODI .. bad idea?

[newfly]

Thinking of connecting the RODI line straight to my RO reservoir, Not brave enough to connect straight to the tank. I have a float switch on the reservoir. my thinking is use a timer (like 5-10mins a day) to top up the reservoir.

I can also get a optical water sensor in addition to the mechanical float valve. I'm using Hydros Control and they have solenoid that works with it. Well, i went cheap and get Hydros 2, which means i only have 2 sensor port. Both is currently used .
- Heater temp failsafe
- ATO top off fail safe (optical water sensor mounter in the DT, turn off ATO power if water reach the sensor)

Since the ATO (tunze 3155) have 2 sensors already, i figure I could use the Hydros optical sensor for the ATO reservoir.

Bad idea? The solenoid for Hydros is normally close. Power on will open the solenoid. This seems safe. Of course it can stuck ON. This is where the float valve and optical sensor comes in.

if i do this, i will also get the Flow-lok Leak Detector just in case.

Any experience with Solenoid for RODI?

How often they fail?

Eventually once Hydros have more sensor probe, i can upgrade the control unit to add more ports.

 

[The_Lazy_Reefer]

I definitely would trust a setup with an optical sensor followed by a mechanical back up float switch. The odds that both with fail in the same time frame is highly unlikely though this is reefing so anything is possible haha.

BRS recommends replacing solenoid shut offs every year. Dunno if that’s a sale tactic or not but my rodi has a solenoid/optical sensor that hasn’t failed in 3 years but I also have a mechanical shut off at the end of the line in case the solenoid does decide to let go.

 

[svreef]

I have it setup this way with an XP Aqua Flood Guardian. Every day, my Apex turns it on for half an hour. The flood guardian beeps and switches on. When it detects that it’s full, it beeps again. I also have a second Neptune optical sensor higher up as a backup. It’s been this way for nearly a year and I’m very pleased with it.

 

[ofzakaria]

It depend on the solniod.
My Neptune solniod (used for ATO) brok in 6 months (few on off events a day) while my dastaco reactor solniod been running st much much higher on off frequency for 4 years.
Solniod switches has bad rap because the market is flooded with cheap low quality products.

 

[RandyC]

Running your RO unit in such small batches everyday will cause your RO Membrane to wear out faster.

I have had three Neptune solenoid auto filling two RO bins for around 3 years now without an issue.

 

[ofzakaria]

BTW one of the things you can check for is heat. If switch heating often thats bad sign.

 

[sfsuphysics]

my thinking is use a timer (like 5-10mins a day) to top up the reservoir.

Very bad idea. TDS creep is a real thing, it takes a bit to get "awesome" water from your RO membrane, and you'll end up burning through DI resin at scary rate. As Randy mentioned above, RO units are meant to run for a while, they're not on/off quick cycle things.

 

[newfly]

Running your RO unit in such small batches everyday will cause your RO Membrane to wear out faster.

I have had three Neptune solenoid auto filling two RO bins for around 3 years now without an issue.

Mine is a tankless ro. It meant to connect directly to the kitchen faucet which I am currently doing. I think it’s design to do small batch . I tee off the ro line and add di stage for the tank.

 

[svreef]

Very bad idea. TDS creep is a real thing, it takes a bit to get "awesome" water from your RO membrane, and you'll end up burning through DI resin at scary rate. As Randy mentioned above, RO units are meant to run for a while, they're not on/off quick cycle things.

What’s “a while”. Mine runs long enough to produce a gallon of water.

 

[newfly]

Very bad idea. TDS creep is a real thing, it takes a bit to get "awesome" water from your RO membrane, and you'll end up burning through DI resin at scary rate. As Randy mentioned above, RO units are meant to run for a while, they're not on/off quick cycle things.

Is tankless RO have the same problem? Forget about the tank, I’m running the RO basically one cup at a time .

 

[newfly]

What’s “a while”. Mine runs long enough to produce a gallon of water.

Mine is a 400gpd unit. 5mins will get me 1 gallon , maybe a bit more . I don’t think I will have issue with small batch since I’m running the ro for drinking , one cup at a time .

 

[JVU]

I’ve been doing this successfully for years, I use the Tunze water controller, which has some redundant safety features built in:

RO Water Controller

Make RO Water production more convenient with Tunze's automated RO Water Controller! The Tunze RO Water Controller 8555 is used to regulate the water level in your fresh water storage container. It uses two float switches to control an electronic valve. When the water level drops below the...

www.bulkreefsupply.com

This made a much larger positive impact on my reefing life than I would have guessed.

 

[ofzakaria]

I’ve been doing this successfully for years, I use the Tunze water controller, which has some redundant safety features built in:

RO Water Controller

Make RO Water production more convenient with Tunze's automated RO Water Controller! The Tunze RO Water Controller 8555 is used to regulate the water level in your fresh water storage container. It uses two float switches to control an electronic valve. When the water level drops below the...

www.bulkreefsupply.com

This made a much larger positive impact on my reefing life than I would have guessed.

Whats on thw dastaco is similar to the one used in the tunze setup. That is a high quality switch..

 

[sfsuphysics]

What’s “a while”. Mine runs long enough to produce a gallon of water.

I think BRS may have done testing on this some time back, but I'm too lazy to look. Although it would be something that is easy enough to test if you have a TD meter, simply take a sample at various points right after the RO membrane (but before the resin) while making water, like every 1/4 gallon maybe, see if you see any difference. If you're running DI resin then the resin should clean up your water, if you're not then you're probably not getting water as clear as you think. Ultimately it's a YMMV situation though as water quality from reefer to reefer in the club differs pretty greatly from the faucet.

Something like John showed off is a great tool, it autofills a container for you, starts when the low point is triggered and stops when the high point is reached, but all of that involves storage of water, which the OP I don't think wants to store.

 

[svreef]

I’m going to chuck the tankless RO and switch to one with a 20g tank. That will help greatly with TDS creep.

 

[ofzakaria]

Why do not you instead invest in a big RODI container then have it connected to your ATO?
I use 65G storage container that I fill with RODI and have my ATO line in there.

If you have a controller you can put some safety like not let it run beyond 10min at a time or something.
Or simply add a float valve to the ATO line in your sump.
I do both.

 

[newfly]

I

Why do not you instead invest in a big RODI container then have it connected to your ATO?
I use 65G storage container that I fill with RODI and have my ATO line in there.

If you have a controller you can put some safety like not let it run beyond 10min at a time or something.
Or simply add a float valve to the ATO line in your sump.
I do both.

It’s a space issue. I don’t have a garage or enough closet space I can put a large RO water tank.

 

[sfsuphysics]

I’m going to chuck the tankless RO and switch to one with a 20g tank. That will help greatly with TDS creep.

Ok just saw some other mentions of this. First there's really no difference between a "tankless" RO unit and one with a tank, functionally the RO part works the same. For kitchen sinks they typically have a small tank that sits under the sink simply because RO production is relatively slow and no one wants to wait for water to be produced to get a drink, so the tank there is to store the water (under pressure) so they have a small amount they can drink at any given time and refill periodically. RO production is EXTREMELY slow compared to the regular faucet, which even a low flow faucet would push out somewhere on the order of 2000 gallons a day, where as an RO unit will be somewhere around 75 gallons a day, hence the reason for a tank under the sink.

Now what us reefers do is we effectively make a tanked system, which basically is a place to store the water except we don't do it under pressure, the tank itself doesn't do anything though for production though. Some use fancy water holding containers (@Coral reefer) others use brute garbage cans, and some even use really fancy acrylic boxes that look super snazzy nice. But you don't need to buy a whole RO unit to do that, you just get whatever container you want to hold the water and run the line from your RO unit to that.

The tank is simply a way to store a finished product and allows you to make a "bunch" at a time, so you don't need to keep turning your RO unit on/off. Now there could be issues with the RO unit itself based on how it's designed, but that's another topic all together.

 

[Vhuang168]

Ok just saw some other mentions of this. First there's really no difference between a "tankless" RO unit and one with a tank, functionally the RO part works the same. For kitchen sinks they typically have a small tank that sits under the sink simply because RO production is relatively slow and no one wants to wait for water to be produced to get a drink, so the tank there is to store the water (under pressure) so they have a small amount they can drink at any given time and refill periodically. RO production is EXTREMELY slow compared to the regular faucet, which even a low flow faucet would push out somewhere on the order of 2000 gallons a day, where as an RO unit will be somewhere around 75 gallons a day, hence the reason for a tank under the sink.

Now what us reefers do is we effectively make a tanked system, which basically is a place to store the water except we don't do it under pressure, the tank itself doesn't do anything though for production though. Some use fancy water holding containers (@Coral reefer) others use brute garbage cans, and some even use really fancy acrylic boxes that look super snazzy nice. But you don't need to buy a whole RO unit to do that, you just get whatever container you want to hold the water and run the line from your RO unit to that.

The tank is simply a way to store a finished product and allows you to make a "bunch" at a time, so you don't need to keep turning your RO unit on/off. Now there could be issues with the RO unit itself based on how it's designed, but that's another topic all together.

In addition, drinking RO systems usually don't have DI as part of their filters. Most RO systems in use for aquariums are RODI systems. They incorporate from 1 to 5 DI canisters after the RO membrane.

 

[sfsuphysics]

In addition, drinking RO systems usually don't have DI as part of their filters. Most RO systems in use for aquariums are RODI systems. They incorporate from 1 to 5 DI canisters after the RO membrane.

Yup, RO systems for aquarium can go from simple to "you have HOW many stages?" but that level of talk is definitely more for another topic.