Have you broken your filter housing mount that your filter cover screws on to? Bestway, the makers of the Bestway, coleman and Lay-Z-Spa lines of inflatable hot tubs, does not sell a replacement for this part as normally it is glued in to the tub. If you contact Bestway, they will tell you that the only fix is to replace the liner at the cost of hundreds of dollars. I have designed a suitable replacement filter mount that is 3D printed from ABS plastic. I am now selling these with a rubber washer to help secure the new mount to the tub. You will need to carefully remove the old pieces, being careful not to damage the threads in the liner of the tub. Once removed, this new part will thread right on giving you a fresh new piece to mount yout filter housing on. You’ll be back up and running in no time.
Another unique feature of this design is the threads that fit into the liner have two flat sides. Sometimes when threading the filter housing on, the outer threads may get locked on to the filter if overtightened. If this happens, the filter mount may come off with the filter cover. The two flat sides of the replacement filter mount allow for the use of a spanner wrench to remove it from the filter housing. Once removed you can thead it back into the liner.