You are a third or fourth generation of Liquidator users here and many of the problems and issues which you may be facing now have been already addressed, discussed, and solved here.
Here are a few tips that may save you a lot of time and aggravation:
1. Hasa’s (the manufacturer) flow indicators leak. Unscrew the two black tube fittings.
Wind on them (counter clockwise when looking from the tubing side) two layers of Teflon tape.
Apply on it liquid Teflon. (Hardware stores carry them under different names).
Screw them back and let them dry for a day. Do not install until they got dry or semi dry.
Make sure that the top cover is screwed tight. You don’t need Teflon there - there’s an O-ring
2. Toss away the original check valves and get new ones from the vendors mentioned in the posts. One of them is American Plastic.
You may need only one check valve – the “In” – coming from the pipe between the filter and the heater.
3. If you have a low flow problem you may want to convert the tubing to 3/8”. Check Rabbit’s post about it. It gives you a list of all the parts you need to get.
4. Hasa’s saddle fitting may be a pain to install and it may leak. Get instead Hayward’s saddle fitting for a chlorinator. It works great.
5. The easiest way to connect the “out” line to the pump is into the pump’s drain plug opening.
Unscrew the plug and replace it with a barb (plastics, not brass!) fitting.
6. Use 12% chlorine instead of 6%. It’s less work!.
7. Paint the Liquidator sides which are exposed to sunlight by spray paint. You’d minimize chlorine decomp in the tank.
8. Be careful not to lose the flow indicator’s ball . If you need any part call Hasa and ask for Frankie (it’s a she) : 661-259-5848 , email@example.com
9. As the level of chlorine in the tank goes down you may need to increase the flow rate because consequently the chlorine concentration in the top solution may also go down.
10. Last but not the least, the “White Stuff” issue.
If you have it and if it slows down the flow, make sure the pH is 7.2. If it doesn’t help add 50 ppm borates as mentioned in the borates posts (look at chem geek’s numbers, I think it’s in the “deep end”.) You may also get extra benefits from the borates.
Some of them are subjective - it's not exact science.