I want to drain a bunch of different things down my basement floor drain: my washing machine and two different fish tanks.
The floor drain already has black abs pipe shoved down it, and a standpipe for the washing machine is attached to it. The condensate pump, utility sink, and washer are all connected to the standpipe that goes down to the floor drain. This all worked well; everything connects to this pipe system a good 2 ft above the floor…
But I also have a fish tank with a drain that needed to go to the floor drain.. This is where trouble began, since the fish tank drain connects to this piping system at floor level… if the standpipe backs up, the fish tank drain backs up. The drain line is about 25ft of flexible 1 inch ID tube.
I changed the plumbing on the washers drain so there was a T going into the floor drain. and then I attached my fish tank drain to the other side. This worked fine with the old washer. Then I got a new washer.
Now when the new washer drains, it pumps water faster than the floor drain can handle without head height, and detergent now backs up the fish tank drain line. So I disconnected the fish tank drain line and I capped the T. So now my drain is like this (actual picture) where the tall pipe that is disconnected, or a cap, is added to the top of the T to prevent the washer from spilling all over the floor.. The flexible tube is coming from the fish tank, and has 0.5GPH flowing down it at all times. Right now it just seeps down the floor drain; it used to connect into the T; but I cannot have washing machine detergent back up into the fish tank. Another angle
As an experiment; I opened the top cap of the T; put a tall pipe in the top cap of the T, and observed that the washer backs up about 8 inches vertically above the floor drain before it has enough head height (?) to drain at the rate the washer is pumping water..
The drain isn’t slow, i don’t think. I can run the utility sink tap full blast and it flows down the drain just fine. It’s the new washer that really pumps water out way too fast….But 1.5 inch pipes should handle thousands of GPH right? So maybe it is slow?
With the cap or tall pipe, this configuration is OK and has been like this for a couple months. But I want the fish tank line to be able to drain more water; if I flow 1.5gph from the tank instead, the floor drain overflows. Furthermore, I want to put another 0.5gph drain line coming from behind the washer, from a different place in my basement.
I’ve thought about maybe putting a check valve in the fish tank line; except I am concerned that snails might block the check valve, that if the check valve fails I’m back at the laundry detergent in the fish tank problem, which is worse than a flooded basement floor.
Over at the wall where the fish tank line enters the laundry room I was thinking about putting a ‘floor sink’ to create an air gap – any washing machine waste could back up into a floor sink located in this corner…
But that wouldn’t solve the question for when I want to add yet another fish tank drain line. I wonder if its not solvable. I wonder if my drain is just clogged.
So the question is; how can I add more fish tanks drip lines to this drain structure without overflowing my floor drain, or sending washing machine detergent up the fish tank drain lines? Is it a venting issue?