float switch failure

[nanomania]

Recently my floatswitch got stuck and the pump remained open and all the water from the reservoir to the tank. fortunately SG went from 1.024-22 as i jus keep a 1gal jug for it and my system is less than 30g. it started working again perfectly once i just shook it. i noticed 1 thing, that there are those tiny featherdusters growing in it. can that be the reason for it??

[fishgate]

I think this is unavoidable with float style switches. The below is the one I plan on getting for my new setup. Better safe then sorry.

http://www.drsfostersmith.com/produc...m?pcatid=24985

[cubalz]

Originally Posted by fishgate

I think this is unavoidable with float style switches. The below is the one I plan on getting for my new setup. Better safe then sorry.

http://www.drsfostersmith.com/produc...m?pcatid=24985

Fishgate: Unless I am missing something, how is the Tunze more "fail safe" that say a JBJ model?

[C Dog]

try using 2 float switches. They both would have to turn on before it pumped

[nanomania]

i guess usin 2 wud be best... any diagram?

[BigAl2007]

Tunze is a top of the line products and very reliable. I've owned JBJ, AUTOTOPOFF.com, and DIY Ato and all failed in less than 18 months. The Tunze have been going for much longer (36 months in Feb if memory serves me well) and it's not missed a lick. It uses an Optical sensor and a Float switch. Built in redundancy is a good thing

If I were designing one from scratch I would use dual Optical switches. All you do is wipe em off 1x a month and you're good to go. Nothing moving to wear out or get hung by a snail goofing off.

[Fishbulb2]

This is why I always advocate putting your ATO on a timer. Set the timer to run one minute every hour and then just increase it until the ATO can just keep up with you evaporation rate. This way, if you ever have a failure, it will take a REALLY long time to flood your sump. Second, if you stick your hands in the sump and make waves, it's unlikely that your ATO will be running at that time.

This is a simple thing to implement and can really save you. If you were using kalk, the ramifications would have been even higher.

FB

[Fishbulb2]

sorry, double post.

[reefgeezer]

I been there. I finally gave up on float switches all together. I use a BRS dosing pump and a Home Depot digital timer.

[Subw00er]

I always use two float switches too. Just wire them together.. take one lead and tie it to one of the second switch's leads. Take the remaining two leads from both switches and wire it back to your controller. That way, both have to be giving the same reading for it to activate. If you really want to be anal and have the room (like in a sump), get a third switch and wire it to your controller and have it shut off the pump when it gets activated (you place it above the normal water line)

And yes, the floats should be totally free of algae and critters. Keep them clean.

[Subw00er]

[dup please erase]

[nanomania]

well the snail can never go there, its built that way.
here is the video: http://www.youtube.com/watch?v=ngl9WXXFSL0

[nanomania]

well the snail can never go there, its built that way.
here is the video: http://www.youtube.com/watch?v=ngl9WXXFSL0

[jay320bird1]

I was having the same problem on my QT. I installed a timer and haven't had any problems since. Pretty easy solution and cost effective.

[Fishbulb2]

Yeah, I am a strong advocate of placing many of these items on timers (in combination with controllers). It is an easy cheap back up as you mentioned. Another application to consider is to place you aquarium heaters on dedicated timers in series with their controllers as well. This way you can limit the amount of time per hour that they are allowed to turn on. For example you can set your temperature to 78 and place the controller or heater on a timer so that it would run just around 80 if the controller or heater ever got stuck on. Basically the timer over rides both the controller and heater to protect your tank.

FB

[Fishbulb2]

Yeah, I am a strong advocate of placing many of these items on timers (in combination with controllers). It is an easy cheap back up as you mentioned. Another application to consider is to place you aquarium heaters on dedicated timers in series with their controllers as well. This way you can limit the amount of time per hour that they are allowed to turn on. For example you can set your temperature to 78 and place the controller or heater on a timer so that it would run just around 80 if the controller or heater ever got stuck on. Basically the timer over rides both the controller and heater to protect your tank.

FB

[nanomania]

But guys i jus have 30mint interval timers i dont have 5 or 15 mint itnerval timers.... what to do?

[jtomasi]

get a cheap controller. pretty much fail safe as most can set a time out feature.

[wildman926]

I use a gravity fed ato with an Eshopps float valve. If it fails, it fails in the closed position due to needing to be cleaned. I have experienced this three times in two years, so I know that is what it does.

[Fishbulb2]

Originally Posted by wildman926

I use a gravity fed ato with an Eshopps float valve. If it fails, it fails in the closed position due to needing to be cleaned. I have experienced this three times in two years, so I know that is what it does.

For additional protection, you could just also set a cheap plastic airline valve in upstream of you float valve. That way you can slow the flow to the sump and if the float valve ever get's stuck open, you would have a much longer time to catch it.

FB

[Subw00er]

Ya but a timer also has a failure mode. What if over time you dont notice the level and its cooler in the house so you get less evaporation than you initially calculated for. There is a chance for a slow overfill situation.

Floats really are the best way, you just need redundancy if you're going to use them. Grainger sells some higher quality float switches that are encapsulated if you are worried about snails or debris.

[Fishbulb2]

Originally Posted by Subw00er

Ya but a timer also has a failure mode. What if over time you dont notice the level and its cooler in the house so you get less evaporation than you initially calculated for. There is a chance for a slow overfill situation.

Floats really are the best way, you just need redundancy if you're going to use them. Grainger sells some higher quality float switches that are encapsulated if you are worried about snails or debris.

If you don't notice your water level changing in the sump over the weeks and months it would take for top off system to get that out of whack with a slow peristaltic pump (like the BRS 50ml/min pump), then you will run into serious problems with any system. You don't need to match the top off exactly with evaporation. You simply tweak it ever couple of weeks by adding or subtracting a minute from the dosing schedule. It took me a couple minutes every two weeks or so with my AC Jr. Changes in your tanks evaporation rate won't happen that quickly. Now I use an autotopoff.com one and just have that on a timer with my AC. If my sump level ever starts to drop, it means add a minute to the cycle. If I ever see it above the marked line, that means the ATO would have failed and the timer is stopping it. No way I wouldn't miss that.

What I advocate is to place your float switch commercial ATO on a high quality timer. The timer serves two purposes, redundancy and convenience (that every time you stick your hand in the sump, you won't kick on the ATO). But for FWIW, i don't think the failure rate on a high quality timer is anything near that of the float switches.

FB

[Fishbulb2]

I would also add that you should also choose your dosing pump carefully when considering your ATO system to minimize any risk. What you really want to do is simply give yourself time to catch any problems when they occur. If you are using a large pump, then even couple minutes of excess dosing could spell disaster. If you are using a very low flow rate pump, like a peristaltic pump, you could give yourself hours to correct anything if you catch the problem. Ideally, you would want a pump (or drip rate for a gravity system) that is nearly always running to keep up with evaporation. That way if the whole automation system fails, you are left with a very slight and slow drift towards a higher sump level giving you plenty of time to catch anything.

FB

[Subw00er]

Actually, the timer + float is not a bad idea, and would reduce possible damage but if the float has failed, you'd still have to catch it before hell ensued! The timer would jsut lessen the blow I guess.

[Fishbulb2]

Yeah, you would need both to fail. In the case of most aquarium ATO, you would likely need two float switches plus the timer to go. Which seems unlikely.

I actually started running my ATO like this not for redundancy but to protect my pumps. I had a nice Buchler peristaltic pump before that I used for my ATO. One day I put my hand in the sump and I could hear the ATO viciously oscillating and it fried the pump. Now it only runs for 5 minutes every hour and it just seldom happens to overlap with me playing in the sump. I've had many a problem with ATO in the past but using a slow pump and limiting it's duty cycle have worked best for me.

FB