Bad experience so far today

Well I woke up and went to check on my tank when I hear a strange noise coming from my sump. I look and to my horror I find my return pump area had run dry. My pump was still running. My ATO pump was still running and my reservoir had run dry. I unplug everything. I check the temp. of the DT as my heater is in the sump and it's about 73, not too bad, but that means the pump had run dry for a while. So I put my heater in the DT to warm the water back up. I also found water on the floor, not too much, but a few gallons. Luckily my tanks in the basement.

Now, why did this happen? The pump was still running, so I didn't think that failed, the ATO was still running and pumped the entire reservoir, about 3 gallons. My skimmer located in the first section of the sump had overflowed, meaning the water level had changed in that section, the tallest section. At first I thought that the return area in the sump had leaked, but that wouldn't have accounted for the skimmer overflowing. I think now that the return pump failed or stopped temporarily, allowing the DT to drain through the return due to the siphon, my check valve apparently didn't work. This overflowed my sump, causing the skimmer to overflow as well. Then my pump started pumping again, but because of the lost water that overflowed the sump, it ran dry and the ATO couldn't keep up with it. (I know it sounds strange for the pump to do this, but I've had powerheads do this before.) I'm currently checking to make sure it didn't leak.

The good news is that all livestock seems to be fine, the fish are swimming and the corals are out. I'll just wait and see. Hopefully it was just the pump acting weird.

 

Hmmm. Are you sure you didn't just run out of top-off water?

 

I'm not really following ya..
Got a pic of the skimmer area?
So all the water is still somewhere in your sump?

 

I'll post a pic of the sump area. I don't think I ran out of top off water b/c I usually use about 1 gallon a day, if that. The ATO would have used 3x that amount in about 12 hours. I checked last night at 9pm and everything was fine. Also, the pump would not run dry in that short of time, if anything the ATO got stuck in the on position, but that wouldn't account for the pump area running dry, even with evaporation.

 

Here's a pic. Hopefully you can see the red arrow pointing to the first bulkhead. That is the highest one, so in order for the skimmer to overflow, the water level needed to be higher then this bulkhead. There's only about a 1/2" of clearance between the top of the bulkhead and the top of the sump. So that's why I think is overflowed.

 

You said the skimmer overflowed, did the air valve get bumped and it over skim (wet skim) to cause your waste cup to OF then the tank try to fill that water loss??

 

That's a good thought, but the air intake was well above the water when I found it this morning. Even if that happened, it would overflow into the sump, and there was enough water in the reservoir to easily handle the additional water that would have been taken up to fill the rest of the skimmer.

 

Thats what I was thinking, also why would you want that wall all the way to the top of your sump, you would want to leave an inch or so for cases like this were the whole tank would just fill up instead 1 part being liek it is and overflow over the top or out the side. Do you have a better pic of the sump not at an angle?

 

maybe...
overflow of water cause the ato water to go into sump, then into dt where it overflowed, when the water in the ato went dry, the sump water went to dt to overflow and then when ato and sump were dry the tank stopped overflowing.

if you can figure that sentence out, +karma to you. That happened to me once, took me awhile to figure out how it leaked though b/c the pitch of the floor.

 

A similar thing happened to me last week. I had a filter sock filled with carbon mounted on the end of my return pipe. As the carbon got dirty the flow was reduced and water started coming out of the top of the sock. Unfortunately for me the sock was close to the edge of my sump and the overflowing water leaked over the edge of the sump. When I woke up I heard the pump sucking air and my ATO reservoir was empty. Luckily it was almost empty the night before and I put off replenishing it until the morning. Otherwise I would have had more water go overboard and a larger drop in salinity.

Do you have any part of your setup that could have done something similar?
Chuck all your fittings and bulkheads for leaks. Maybe your return pipe is leaking somewhere which would also cause the ATO to empty.