auto-top-off units...

[aweeks95]

anyone know of any auto top off units that i can hook up to my ro/di filter? looking for something farely inexpensive but proven reliable


ANDY

 

[marco67]

I would advise against plumbing your ro/di directly into your tank, especialy using an inexpensive controler.
Instead use a secondary container and think fail safe.

 

[aweeks95]

ok...are there any fail safe switches i can use that any of you have used and have good luck with? i'd like to try to set up a float switch with a pump in a secondary container. i would hait to have a switch that could get stuck "on" and overflow the sump....any ideas? i would need a small float switch set up because i'm limited in my sump for area....i have pictures of my sump in the DIY forum if anyone needs to visualize the space i have to work with. i want to try to put the switch in the return pump area.

ANDY

 

[nunofs]

I'm using a double-switch unit from http://autotopoff.com and am happy with it... they also sell a RODI solenoid for the kind of installation that you had in mind, but I agree with Marc that it's risky to plumb your RODI directly to your sump, no matter how many failsafes you have in place.

Nuno

 

[marco67]

As an example
1st; I never run directly from an Ro unit (some people do and never had a problem) I just don't think I could sleep nights.
2nd one simple and cheap fail safe I always use is no mater what controller your using and what kind of pump run it into your sump through a float valve. As an add on to that idea add a presure switch before the float and feed what ever pump your using through it. This way if the sump fills to an unacceptable level water stops flowing and the pump shuts down.
3rd Another thing I do is feed my top off pumps through a PH controller 8.7 and no more top off please! (I learned this one the hard way!)

 

[nunofs]

For clarification, I'm using that double-switch but it's not plumbed directly to the RODI, it just controls a pump that draws from a small water storage container (holds about 10 gallons).

Marc: can you explain what the benefit of your last point is (the pH controller)?

Nuno

 

[aweeks95]

nuno....that double switch looks like the way to go...i wonder if anyone else makes the same type of switch for less jing!!! i'll look and if anyone else knows of any, let me know...thanks guys!!!!!!!!!!

ANDY

 

[denvig]

Here are som units that are good. I use the Reef Fanatic Level Controller w/2 Float Switches one to turn on and a second to turn off if the first one sticks. It has been working great for a year now.

SpectraPure Single Tank Liquid Replenisher (LLC-S)
http://www.spectrapure.com/St_alc_p1.htm

AquaMedic Aquaniveau Level & Refill Control
http://www.aqua-medic.de/index0.html

Tsunami AT1 Top Off System
http://www.championlighting.com/e/e...link=/Products/productinfo.html&item=main:at1

Tunze Osmolator Universal 3155
http://www.tunze.com/usa/index.html?lang=en-gb

Reef Fanatic Level Controller w/2 Float Switches
http://www.premiumaquatics.com/Merc...ROD&Product_Code=RF-RFLC&Category_Code=Dosers

 

[marco67]

Marc: can you explain what the benefit of your last point is (the pH controller)?

Nuno

It's common to dose Kalk with top off, in a floatvalve, float switch or controller failure the PH controller would shut down the top off pump before this Happens.
And I promise you.... you don't want that!

 

[marco67]

Man It's been a year and a half since that and looking at the pics (pg #2 of that post) still makes me feel sick.


Guess it's obvious now why I strongly recommend redundant fail safes?

 

[nunofs]

It's common to dose Kalk with top off, in a floatvalve, float switch or controller failure the PH controller would shut down the top off pump

Ah, I was thinking of pure RODI, was having trouble seeing how the pH would go up... but for kalkwasser it makes a lot of sense.

Nuno

 

[marco67]

Yea I guess I could have been more clear ....it was a thought expanding on the secondary container thought.

 

[smcnally]

I know what you are all saying about the secondary container, but I don't necessarily agree with it. I think it just adds one more mechanical spot that could potentially fail. If your float valve sticks in your secondary container than that can overflow, and if your switch sticks in your sump, then it will still overflow because your secondary container will keep replenishing what is being pumped out of it. I am using a "Yard Bird" 24VAC actuated sprinkler valve that I bought at Lowe's for $14.00 to turn my rodi on and off before it enters my kalk reactor which then feeds into my sump. I'm doing mine a little different than everyone else I've seen though. I'm wiring it kind of backwards. Mine will only open the valve when it sees no voltage across the float switch (I'm operating it manually until I get a switch). So, what happens is if for some reason the float fails, the watter will continue to rise a couple more inches until it hits my screw terminals for the wires. When that happens, it shorts the wires (like the switch would) and still shuts the valve off. It's pretty much a double safety. I've thought about this long and hard, and this seems like the safest way to me.

 

[aweeks95]

safe for water over flow, but what about voltage in the tank? seems unnecessary to have the water short aout a switch....low amps or not. maybe i'm wrong....has the switch stuck yet? has the water had to short out your switch?

ANDY

 

[smcnally]

safe for water over flow, but what about voltage in the tank? seems unnecessary to have the water short aout a switch....low amps or not. maybe i'm wrong....has the switch stuck yet? has the water had to short out your switch?

ANDY

I don't have the float switch in yet. The water wouldn't short out the switch, it would short the contacts that feed to the switch which will be fed 5 Volts DC with extremely low current. I don't think a voltage/current that low would bother anything in there, and even if it irritated anything it would be a lot less irritating than a tank overflow combined with the water salinity dropping. I had a faulty sensor that put 24 Volts DC into my tank and it only seemed to irritate my BTA a little (it started roaming). Plus, it isn't something that should ever happen. It will only happen if the switch fails.

 

[marco67]

then it will still overflow because your secondary container will keep replenishing what is being pumped out of it.

In the system I describe the RO/DI unit never remains "hot" there is just no reason for it to. Besides the risk to your tank / top off system, leaving poly tubing pressurized is asking for a flood. (Learned that from EXP also )
A simple hour or two a week of filling the secondary container and your all set. If you want automation then set it up on a timer to come on once or twice a week for an hour.

Mine will only open the valve when it sees no voltage across the float switch

Again IMO asking for trouble using a normally open valve here means in a power failure or switch failure you are allowing unlimited flow into your sump

 

[aweeks95]

it sounds like it would work fine then....good idea...would you recomend this type of set up to others? if so could you get some pics and post them here...i'd love to see the set up


ANDY

 

[nunofs]

A simple hour or two a week of filling the secondary container and your all set.

Exactly how I do it too, I just manually fill the storage container once or twice a week. That way the biggest flood you can have is the size of your storage container.

Nuno

 

[marco67]

That way the biggest flood you can have is the size of your storage container.

Nuno

LOL Exactly and it helps you decide what size wet vac to by too

 

[objectfire]

For the top-off supply, keep it simple and failsafe: Manually fill your secondary container.

For delivery to your sump: Use a double failsafe system with two distinct mechanisms, e.g. a unit with both mechanical and visual water level sensors.

This is not an area to scrimp on money, as failure is not an option: You can easily kill off your entire tank with an unattended malfunction.

Kent