How much water can evaporate before your sump sucks air?

[RAJOD]

Originally Posted by ridetheducati

Not sure where this thread is going, but was the OP original question answered?

Its a discussion on the merits of small return chamber vs larger ones.
Many things to consider. Evaporation, auto top off, do I have room for extra water under the sump for that etc.

Gathering information before I spend 1k on new sump.

[RAJOD]

Originally Posted by brad_G

A large return chamber is worse than ato. If your overflow fails for any reason you're gonna have a heck of a mess with a 125g return chamber!

Brad in my case I won't have a mess. I have a floor drain with catch all in my sump so all 300 gallons would drain down there.

If my return failed I think the most I would get is 17 gallons. It would take the tank breaking or a pipe breaking which could happen with small or large return.

[brad_G]

My return chamber is maybe 4g. I made it small so that my ato will kick in at the slightest drop of water and so that if a snail or fish get in the overflow it will not overflow the tank. Even with the 5g ato bucket it won't overflow.

[d2mini]

Originally Posted by RAJOD

The issue is where to put the extra water for the auto top off. Its a 360 degree walk around tank. All sides are for viewing the fish all sides same view. The center is an island with overflow in center all hidden. It has dry well in center for running power down. So everything must be in the stand area. or above the tank.

I hear ya, man. That's tough.
My last tank was the same way (with a corner overflow that contained all electrical and plumbing). But even though it was full walk around, it was only a couple feet from one wall. So I ran a bunch of 1/4 water line (3 lines total) behind my baseboards and then across that small section of floor, hidden under a piece of trim that matched the carpet tiles i had around the tank.

[Kyuss]

I think it really comes down to if you have an ATO or not, and how often you check in on it. I can lost about 2-1/2 gallons before I start sucking air, that's 2-3 days worth for me. My entire setup is in the basement, and my sump is on the other side of a wall from my tank under a 4' tall bench (thats strictly for fish related stuff) and isn't enclosed so it's easy for me to give a quick glance at when I'm prepping food or the like each day. I have triple redundancy on my ATO, and if(when) it fails it's almost certainly going to be in the off position so the bigger concern for me is the pump sucking air, not overfilling, so it works out great.

In previous setups I always manually topped off... never again.

[RAJOD]

Originally Posted by d2mini

I hear ya, man. That's tough.
My last tank was the same way (with a corner overflow that contained all electrical and plumbing). But even though it was full walk around, it was only a couple feet from one wall. So I ran a bunch of 1/4 water line (3 lines total) behind my baseboards and then across that small section of floor, hidden under a piece of trim that matched the carpet tiles i had around the tank.

When I had the tank built I was more concerned with getting all the dimensions correct so it fit perfectly. But I did not put a ton of thought into the sump area as the company making it said they would handle that part.

I even had hot cold water faucets plumbed in the ceiling. Then found out too many phosphates in the water so they were sort of a waste. But maybe not.

This might be stupid but I could hook a RO unit in the ceiling to one of the faucets. Then run a small line down through the dry area of the overflow to the sump. But this could potentially be a big mess if it failed as it would be water coming from a faucet.