melgoi

so had this same issue on an intex. the intex tube A does not seem to have the spot to attach any of the plugs i've seen available. I went looking for a backflow preventer and found that lowe's has some pvc check valves for pools and hot tubs. however upon physically seeing them I was not sure they would fit into the tube on the intex. on the intex tube A the part coming from the pump inserts into the part coming from the tub so anything would have to actually be insertable and not take up extra room in the tubes or else you wouldn't be able to screw the tubes together. while in lowes i looked around to see if there was anything else i could try. what i can up with was Stop N" pop lavatory stopper. (the one for the sink. the tub one wouldn't fit). the tube coming from the tub seems to have a place that is a little smaller in diameter inside. i assume that is to prevent the tube from the pump being inserted too far. i placed the stopper against that part with the pop up top toward the tub. then i inserted the pump tube in as usual and screwed it down. just did it yesterday but so far it seems to work. air flows past the stopper and I'm not seeing any signs of water coming back through. this was important as without stopping the flow of water you couldn't use the air pump to pump up the tub nor the bladder without danger of putting water in where there shouldn't be any.