ATO Horror Stories

iLLwiLL

iLLwiLL

Codename: Dutchess
I have heard a lot of people say "I have heard bad things about float valves / switches" but they never have any personal experience, nor can they provide a link to any kind of thread that reflects as such. Does anyone have personal experiences with a float (valve or switch) going bad and causing some kind of disaster like a saltwater tank going fresh, or flooding?

What I would like to know is how these problems could be avoided if they are as bad as everyone thinks they heard someone say they were one time. Maybe there is a particular brand of float that fails more often, or something to do with how it was installed, or the age of the failed unit.

~Will.
 
I bought a Tunze Osmolator 2.5 years ago and have not had a single problem with it. For any ATO, there's a potential for it to fail, but I think it's more of a fear than an everyday occurrence.

I've also heard many horror stories about how an ATO can fail, but only a couple were first hand accounts. Those were situations where the people had their RO/DI unit directly connected to their tank for top-offs and the float valve failed to close. Their sump flooded and it dropped the SpG real low, killing their livestock.
 
Of course, a float switch or valve can fail. If that happens on a badly designed system, it could be a disaster. Set your system up with a little planning and backup contingencies and you'll be fine.

My ATO for example replaces evaporated tank water in the sump by reading the open or closed states of two float switches. Should the switches fail, the RO water entering the sump passes through a float valve that is set to stop the flow if a certain level is reached. That level is just a little higher than that controlled by the float switches. In this way, both switch and valve would have to fail at the same time for any disaster to happen.
 
Eggs Zachary.

I built my own controller that uses two switches to control the pump. The pump, even if both switches fail, can't dump more than 5 gallons in to my tank every two days.

I use a programable sprinkler timer to fill my 5g top-off reservoir every 2 days. The controller cycles a pump, in that reservoir, when switch A opens. Switch B is a failsafe and will turn off the pump in the even that switch A sticks. If switch A is working properly, switch B never gets tripped.

I've been using that system for almost 5 years and while I've had a couple of component failures, never had a flood or a "disaster."

If you plan for failures, you're not surprised by them.

Cheers
 
beerguy - what kind of component failures? any idea what caused them i.e. a barnicle, salt creep, age, a snail, bigfoot, etc.

I understand the ideas behind fail safes, and appreciate the comments thus far. what I'm really looking for is ANY first hand experiences or links to these things failing and why it happened.

~Will.
 
<a href=showthread.php?s=&postid=15490521#post15490521 target=_blank>Originally posted</a> by iLLwiLL
got any links or any clue what caused the float to fail to close?

~Will.
Click to expand...

Sorry, no links or other info really... Most of what I've heard was told to me by other hobbyists in person at local meetings. I didn't ask many questions on the hows or whys, perhaps because at the time I was confident that I would just plan for failures and find ways to prevent them. The simplest thing I did was to not set up an overly large top-off reservoir. If my ATO completely failed and kept pumping fw, it would at most pump about 6 gallons (when full) into a system that has a total water volume of about 100g. I fill that reservoir every 5 - 7 days, depending on the evaporation rate at the particular time of year. An extra 6 gallons of fw would certainly not be all that good for our tank, but I don't feel it would result in our tank crashing.
 
Float switches are generally magnetic reed switches. There is metal that flexes each time the switch is opened and closed. Every piece of metal has a finite number of times that can happen before it's going to break. I've had a couple of switches fail but the system has always worked as designed.
 
I have the most "ghetto" ATO I've seen but it works well. I got a float designed to fill horse troughs from a livestock supply store. I hooked up my RO unit directly to it, which I know most people think is a bad idea. I put a solenoid in the line though, so it only runs for 10 minutes at a time twice a day. In the event that the float got stuck open it could only run for 10 minutes before the solenoid closes and it is at a really low pressure, so not too much water comes out over a 10 minute period. I've never had a problem with this.
 
I don't have any links saved, but over the years I've read several RC threads about failed ATO's that have caused tank crashes.

Joyce
 
I had an ATO fail. A simple single float switch on a small pump. The float switch stuck a few times in the up position, so the sump ran dry. That is not a big deal unless you are out of town. One time it stuck in the down position and pumped a 20 gallon tank of fresh water into my sump. Well, the sump only held an extra 10 gallons and the other 10 gallons went on the floor. 10 gallons spreads a really long way! It only happens in the middle of night and being yelled at does not help clean it up.

My setup now has two switches and uses a dosing pump. The addition of top off water is very slow so if both switches failed (unlikely) it would take quite a while to get into trouble. I have considered adding a 3rd layer of protection but it probably isnt needed.

I am an idiot and have flooded the house/apartments several other times over the years. it turns out that idiot proof is pretty hard to do. I know leave nothing to chance. everything has a back-up. I am not sure my wife would tolerate another flood.

Redundancy is the key.


good luck
 
Living on the edge here, simple humidifier float valve connected to my ro/di coming up 4 years without a problem. Nice, simple mechanical valve, no wires, controllers etc.


Figure never heard of a basement getting flooded because of the humidifier. If anything they usually don't open because of buildup, so continually rinsing with ro/di a good thing.

.
 
I have several - the ones that depend upon air pressure backing up in a tube have failed me several times but that is because they have lousy suction cups and move. The float valve type are more reliable - they can get stuck in the off position when they get really old and crusty.
So now, I use 2 - one air tube type with a float valve as safety - and the water comes in through the float valve (keeping salt creep off it).

I REALLY WISH I had a drain in my sump room floor. I have mopped out water way too many times - my least favorite part of the hobby
.:( :eek: :(
 
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I also would like to install ATO, but I want to do it idiot proof. If I do it I will use two or even three switches and Aqua Lifter pump. Someone if selling pressure switch, i forgot who, but I looked like a good idea. No moving part to get stuck although I am not sure how accurate that switch is. Right now I just use Aqua Lifter pump on digital timer. I only runs 6 times for 1 minute every 4 hours. I have to adjust salinity, usually on weekends due to different evaporation rate. My RO container is about 4 gallons so every few days I need to refill it. This system worked flawlessly for last four years. It is not perfect but works. I am in the process of designing new sump, I almost saved up for ATB cone skimmer, and need larger sump. This time around I will buy ATO, but It will have at least two float switches and pressure switch as a backup. Also I will keep my 4 gallon RO container and only when on vacation I may use something larger or have a friend refill it. IMO ATO is not necessary for good reef tank, but make life a bit easier. One time I left my reef tank for two weeks when I was out of country without anyone tending to it. Not a single fish or coral lose. How I did it? I lowered settings on the chiller to 76 F and bought a lots of digital timers to rum feeders and other equipment. LOL
 
IMHO the Tunze Osmolator is virtually bullet proof. Sure it's pricey but you are buying a piece of technology that is tried and tested over the years and you'll be leaving your tank knowing that a ATO horror won't await you when you get home.

-TDF
 
If you have the possibility of hooking up to an RO DI system, it is easier - but DO use at least 2 off switches.
 
over the years, i have read several several threads of peoples destroying their tanks via ato...esp if it is connected to a kalkwasser reactor.

i dont bookmark threads or rarely go back to read subscribed old threads (esp really long drawn out ones). so, sorry, youre just going to have to take my word on it.

dave b had a reverse ato tank crash. his tank had a leak that allowed the ato to constantly top the tank off with fw.

thus...

after years and years of reefing...i am finally going to set up an ato...but not connected to a kalk reactor or directly to the ro unit. my 180g (300g total adjusted volume) will have a 30 gal rodi reservoir and my 90g (about 96g total adjusted vol) will have a 10g reservoir. if the ato float fails, i will dump a lot of fw in...but not enough to kill the tank.

btw: every ato failure i have read about occurs at night, at work or on vacation.
 
I have heard all of the horror stories too. This is one of those items you don't "go cheap" on. I hooked my ATO up to an RO system over 2 years ago and it is probably one of the best moves I have ever made. When there is potential for disaster you have to build in some redundant fail-safe measures though. My system uses a electric float hooked up to a solenoid valve, if for any reason the electric float fails there is a mechanical float in series with it, if that fails, the solenoid is hooked to a timer that comes on for 15 minutes twice a day, and my RO system can only pump about a gallon of water in that period of time. My sump has about 12 gallons of headroom.
 
I have personally had a float valve fail. It is a Kent marine one and it continues to fail so now I dont even use it. Its only purpose is to fill up my ATO container and so I left the RO running into the container overnight thinking the float valve would stop it and sure enough it didnt. 11 gallons all over my carpet luckily all fresh.

I still havent been able to figure out why a "float" valve doesnt always float?!?!??! sometime it works sometime it doesnt. Now I only refill my ATO container when Im home and I set an alarm so I dont forget. big PITA and I plan on fixing that issue when I move soon.

As for the top off of my sump, Ive been using an autotopoff.com float switch for 2 years now with no issues whatsoever. Its pretty unlikely that two float switches will fail and one is on top of the other so I feel pretty safe with that.

Ive know plenty of ppl that use the digital timer/ pump combo and that works well unless your digital timer fails (its happened). Also, some days your tank may evaporate more than others and your salinity can change quite easily.

Ive heard the Tunze Osmolator's are awesome. That maybe my next big purchase.
 
most problems i have seen are DIY projects no or little maintenance as cleaning float assemblys or solenoid valves, suction cups coming loose or holder. snails on floats, The biggest is a mechanical floats as kent floats or same type. To much of a load on a 300ma float switch using it to turn on and off a pump.
 
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