RODI plumbed to sump - pros and cons??

[Perfectly_Imperfekt1]

Fellow reefers,

What are the benefits and disadvantages to plumbing the RODI directly to the sump? I spent some time searching for the answers and didn't find what I was looking for. BRS has a video on RODI, but it wasn't in detail on this subject.

My current setup I have a water reservoir and fill that every 12-14 days. My RODI water setup is in the garage. So if needed, I could make water for saltwater changes( I don't do, I'm doing moonshine method for 2 years now), emergency water, etc.

The plan is to put the RODI under the sink and run the line through the wall to the sump. Then hook the line to a float valve. There are some thoughts of sensors for the just in case crap happens.

Please share your opinions or experiences in RODI straight to the sump. Thanks for looking.

 

[Reefering1]

Search "tds creep"

 

[Gtinnel]

One concern is tds creep with the unit turning on many times a day. You will quickly use up your di resin unless you can find a way to put the permeate water down the waste side for the first few minutes everytime it comes on.
The other concern is that you have an unlimited fresh water supply. If your rodi fails on (everything fails eventually) you can reduce your salinity and overflow your tank/sump.

 

[DrMMI]

I have a very large (200 g) reservoir of rodi in my basement. I fill my 200 g reservoir directly from the rodi unit. I then use a pmup to keep my ato reservoir in my cabinet full. I have multiple safeties built in to make sure I don't end up with replacing my 260 saltwater aquarium with 200 gallons of freshwater. Definitely worth never having to haul buckets to fill my ato reservoir and my wife appreciates keeping spilled water off the hardwood. I only ever run my rodi unit when I need to make a new batch of saltwater, so no risk of tds creep and burning up my di resin in order to keep my ato topped off.

 

[Panda Jerk]

One concern is tds creep with the unit turning on many times a day. You will quickly use up your di resin unless you can find a way to put the permeate water down the waste side for the first few minutes everytime it comes on.

Actually, you burn the same DI resin regardless where you discharge the permeate. The difference is by dumping it you don’t add the initial higher concentration TDS water into the tank (i this is what you meant but wanted to clear it up). Gotta have an intermediate reservoir to dilute it with bigger batches unless you can dump the initial minute(s).

 

[mfinn]

Besides going through more di resin, my other thought is what if the float switch on the rodi failed? Stuck open at the wrong time?

 

[Panda Jerk]

You can’t protect against everything. I have 2 solenoids in series on the feed line to my RODI reservoir. Still could fail. I think the service life of a cleaned float would outlast the ensuing plague of TDS creep. There are a few water wizards here that have posted on the topic. @Buckeye Hydro wanna chime in?

 

[Gtinnel]

Actually, you burn the same DI resin regardless where you discharge the permeate. The difference is by dumping it you don’t add the initial higher concentration TDS water into the tank (i this is what you meant but wanted to clear it up). Gotta have an intermediate reservoir to dilute it with bigger batches unless you can dump the initial minute(s).

How is that if I put the initially high tds water down the drain before it goes through the resin that it still depletes the resin?

No I meant that if you dump the water between the membrane and the di it will prolong the life of the di because you are waiting for the tds to drop before putting it through the di resin. I have a solenoid valve setup on my system that the water for the first few minutes of the unit turning on do not go through the di and get put down the waste drain. Maybe my post didn’t make that as clear as it was in my head.

 

[Panda Jerk]

Yes, that’s the key. Have to discharge before the DI. Maybe I missed that in your post.

 

[Gtinnel]

Yes, that’s the key. Have to discharge before the DI. Maybe I missed that in your post.

I just used the term permeate to mean the water coming out of the membrane and could have been more clear that I meant before it goes into the di because the final output water is still permeate.

I could’ve been more clear, but either way it is cleared up now.

 

[mfinn]

You can’t protect against everything. I have 2 solenoids in series on the feed line to my RODI reservoir. Still could fail. I think the service life of a cleaned float would outlast the ensuing plague of TDS creep. There are a few water wizards here that have posted on the topic. @Buckeye Hydro wanna chime in?

I have learned that if I can find a way to eliminate a weak point it's better to do what I can before it happens.
I'm sure there are many points to be had on whether to plumb the rodi directly to the system or not to do it, I would not. IMO not worth it.

 

[Buckeye Hydro]

Yep - concerns in the thread are on the money with concerns re TDS creep and the potential to flood your sump with fresh water. There are many work-arounds including 1) filling a small reservoir once a week with 1.1 times weekly top off amount, and have that small reservoir gravity drain to a float valve in the sump; and 2) using an electrical circuit on a timer to control a solenoid valve on the RODI feedwater tube.

Personally I like No. 1, and I used it successfully for ~20 years with a 300g system.

Russ

 

[gbroadbridge]

Fellow reefers,

What are the benefits and disadvantages to plumbing the RODI directly to the sump? I spent some time searching for the answers and didn't find what I was looking for. BRS has a video on RODI, but it wasn't in detail on this subject.

My current setup I have a water reservoir and fill that every 12-14 days. My RODI water setup is in the garage. So if needed, I could make water for saltwater changes( I don't do, I'm doing moonshine method for 2 years now), emergency water, etc.

The plan is to put the RODI under the sink and run the line through the wall to the sump. Then hook the line to a float valve. There are some thoughts of sensors for the just in case crap happens.

Please share your opinions or experiences in RODI straight to the sump. Thanks for looking.

I love it.
I travel a lot and having the RODI directly plumbed means I dont have to worry about tank top off's.

I use the Aqua One Smart ATO RO.

It refills the RODI reservoir when it is almost empty (10 gal reservoir).
The ATO itself pumps from that reservoir.

It has two optical sensors (one at the bottom of the reservoir to turn on the solenoid valve attached to the line from the RODI filter and another at the top to determine when full). Because of this design there is no additional TDS creep.

The RODI line is attached to a float valve in the reservoir which will prevent the system from flooding if there is an electronics or sensor failure.

Been running for almost two years now with no issues.

AUTOAQUA

www.autoaqua.com.tw

 

[vabben]

I have a very large (200 g) reservoir of rodi in my basement. I fill my 200 g reservoir directly from the rodi unit. I then use a pmup to keep my ato reservoir in my cabinet full. I have multiple safeties built in to make sure I don't end up with replacing my 260 saltwater aquarium with 200 gallons of freshwater. Definitely worth never having to haul buckets to fill my ato reservoir and my wife appreciates keeping spilled water off the hardwood. I only ever run my rodi unit when I need to make a new batch of saltwater, so no risk of tds creep and burning up my di resin in order to keep my ato topped off.

This is what I do as well. My apex automatically fills my 5gal container that sits next to my sump utilizing a pmup in my 100gal RODI storage container in the basement. Multiple safeties in place and has worked flawlessly for 2years.

 

[Buckeye Hydro]

This is what I do as well. My apex automatically fills my 5gal container that sits next to my sump utilizing a pmup in my 100gal RODI storage container in the basement. Multiple safeties in place and has worked flawlessly for 2years.

Do you have something in place to make sure the RODI doesn't short-cycle to keep that reservoir filled?

 

[Gtinnel]

My ATO refill system is a little unorthodox but I had it setup to where it would autofill my 20ish gallon ATO once it was empty with zero chance of overfilling the reservoir at the tank. It is/was a diy fully automated system that had solenoids to dump the initial output from the membrane and bypass the restriction to periodically flush the membrane. It worked well for several years without me ever having to touch it. The hardest part about my setup was I had to find some time when it was running to check tds and pressures to see if filters needed replaced.
Then one day I noticed it running and several hours later I noticed it still running which was odd. As it turns out one of the solenoids in my system failed open which caused it to run and all water go down the drain. With the system being fully automatic I don’t know how long it ran dumping all of the water down the drain before I caught it. This system is in an unfinished utility room away from the tank that I don’t even go into for several days at a time so it may have taken days to catch. My system now does everything it used to except I have to manually start it running then a little bit later I turn the water and system back off.

This entire long winded explanation of my system is essentially to warn anyone with an automated system to consider things like a solenoid failing. How much damage to your tank or home, or water could be wasted if a single solenoid failed. A fully automated system now terrifies me regardless of how many failsafes there are, because eventually everything fails. At least when mine failed all it did was waste some water.

 

[slingfox]

To automatically deal with TDS creep you can use the Smart Buddie RODI booster. It flushes the water between the membrane and DI stages for 18 seconds every time the unit turns on as well as once every 24 hours.

 

[FranklinDattein]

IMO, RODI Automation is worth every cent, but also a common cause of tank crashes.

As others said before, most of the problems can be mitigated if implemented correctly.

Below is the diagram of my early version.
RO Side:
The RO is connected to a solenoid that is controlled by a XH-M203 circuit from Aliexpress, with two float switches. It is basically an ATO with low and high float switches. If the top float switch fails, the float valve together with the back pressure valve will stop the RO.
Additionally, the solenoid is connected to a timer that limits the amount of time it is allowed to run. This is to reduce the amount of water leaking, in case of an accident while nobody is home (it saved me once).
Finally, there is a leak sensor underneath it.

Not in the diagram, there is also a extra solenoid to flush the RO every time it starts for 3 minutes and avoid TDS creep.

Aquarium side:
On the aquarium side, there is a regular ATO that triggers a peristaltic pump that sucks water from the reservoir. Most people will use a small pump for this application, instead.
Next, there is a second pair of float switches connected to an aquarium controller, for monitoring purposes. It sends me alerts of low and high water, in case the main ATO fails for some reason.

The main ATO can also be plugged to the controller's power outlets, in case you want to be able to stop/restart it remotely. I had a flimsy ATO from kamoer that needed frequent restarts, but I wouldn't recommend that as it becomes a single point of failure.

In the new version I made it much simpler and dead silent, by replacing the bucket reservoir with a pressurised reservoir. This allowed me to get rid of the peristaltic pump, the XH-M203 and the float valves in the bucket.
Unfortunately, I don't have a diagram for this version.

The redundancy makes it fairly complex, but if you remove it, is basically and ATO and and RODI on timer and with a pressurised reservoir.

 

[mattnano]

According to the late great Jake Adams float valves are the way to go for ATO because there are much less points of failure and it’s cheap enough to swap out float valves once a year. The way I implemented mine was to have my large R/O container plumbed directly to a float valve in my sump. I have the R/O flood guardian hooked up as backup just incase there is a failure and I’m not around.

 

[Perfectly_Imperfekt1]

To automatically deal with TDS creep you can use the Smart Buddie RODI booster. It flushes the water between the membrane and DI stages for 18 seconds every time the unit turns on as well as once every 24 hours.

This was my thought, and use this with a float valve in the sump. Then add some sort of leak detection is always a plus.

Appreciate all the input on this thread.