DIY ATO Float Valve

Here is my version of the Auto top off. I just picked up a clip on 1" 'T' fitting to 3/4" pvc that fit perfect on my reserve return tubing going back into the sump. I also got a float valve, 1/4" bulkhead, and 6' of 1/4" tubing from bulk reef supply. I just cut out the bell of the pvc for the float valve. The issue I see down the road would be salt creep, but as for now it's topping off right on the money. Total cost 28$

 

I am wondering if you foresee any problems other than salt creep with this design? I had planned to build a ato using a float switch but I can only find them online and dont want to wait on shipping.

 

It looks as your top off water tank is above your sump, when the float sticks, and at some point it will, you will have a flood.

 

Well I did think of that, and for a cheap diy it'll probably be temporary. But I do not fill the fresh water bucket completly up and it doesn't have enough to fill the sump tank. I will be cleaning the float valve periodically so I'm not worried as of yet. Thanks for the info though.

 

Why do you feel that the float will stick? As long as it is kept clean, not allowed to corrode or build up salt creep it should be fine right? I would like to build once of these this week thats why i ask.

 

It's a very small valve that shuts the water flow. Usually not associated with much water flow. I suppose if you are dilligent and can keep it clean you will beet the odds. It is a good valve, I use one to shut off my RODI water but it's in my garage.

 

I like it! I've used float valves just like that for years with just simple gravity fed reservoirs. I've never once had one stick open. At times salt creep will cause them to stick closed. I too only ever have enough water in my ATO so that if something happens the volume of fresh water added can't cause problems. I'm not so much worried about a flood as I am about diluting the SG. I will never run an ATO that is attached directly to an RO unit for this very reason. I understand redundancies and all that, but I've seen enough tanks nuked due to an ATO dumping too much water that it's just not worth the risk to me. I'll gladly top off the reservoir every few days for the peace of mind.

______________________________________________

​

 

I had planned on using a small container as well that doesnt have the potential to dilute the tank with too much fresh water. And the amount of pressure from this gravity fed container would put no significant strain on the shutoff valve. So should be fine. Excellent.

 

Nice job. Thanks for sharing. If kept clean there is no reason why it would fail.

 

I run gravity fed ato's as well and had never had an issue.