Pump size

can I fix this then?

Oh yea they are sorry your right I thought you meant T'd down they both are T'd on the top. One of them does have a vent hole.. its actually like a little siphon thing... I don't use it.. its really weird the guy explained it but it confused me. I just wanna re do this whole thing. It works but, its just a hassle to have to re adjust it after ever water change. the other drain pipe doesn't have a vent hole and neither are adjustable.

 

This is more than likely your whole problem. That "little siphon thing" is on there for a reason lol. As to how it exactly works, you'll have to ask someone else that knows more about your setup. Or post some pics of it and maybe I can help. Is the one thats sealed, the same drain that is split to run to your fuge?

 

lol yea the little siphon thing just confused me! Im not a plumber.. I wish mario was real. haha I can take some pictures of it, but the water level in the over flow has to be really high for it to work I have had it working and siphoning, but I still had the same problem. so then after that I just left it alone because it was the same either way... And yes the one that is sealed is the same drain that is split to run into the fuge I will take some pics of the "little siphon thing"

 

In my opinion, this setup just needs slight adjustment.

First, the vented drain should be the one split to feed the fuge.
The second drain is the safety; if the first fails in anyway, the second drain will create a siphon (and an alerting flushing sound).

Additionally, if you need to 'tune' the vented drain . . . drill (~3/8") the cap to accept a 1/4" threaded john guest fitting, piece of air line (1/4" tubing), & 1/4" valve.
This allows you to tweak the amount of air entering the vent. Makes is almost completely silent . . . only negative is sometimes you get salt buildup in the intake - but it's easily fixed with a quick rinse with tap water.

The drains should be easily be swapped thanks to the unions/bulkheads.
Are the bulkheads at the exact same height or is one lower than the other?
(by the way . . . if you don't want to see a silly 1/4" air line and valve sticking up on the drain, you could probably drill the side of the cap, but you'd need to plug the original vent hole.)

Just my 2 cents.