Unsure of pump issue

Hello. Trying to help my neighbor with a 27' round above ground, filter is a 1hp hayward proflex and a big round sand filter. Not sure of the pressure as his gauge appears rusted on the inside, a new one is on order. Note I am comparing my experience to my in ground pool also with a 1hp pump.

As we are starting his up, the water flow coming in seems very low and the strainer basket only fills halfway up. He bought a crawler type cleaner and it barely moves. I can hold my hand to the end of the line and feel very little pump pull. If we take the crawler hoses off, the water flow is higher and the basket never fills beyond halfway up. Compared to my pump, mine fills all the way up, no air, and the suction will hurt if you get your hand too close. We have replaced the lid seal and checked for air leaks and can't find the obvious. Is the basket not filling up normal for above ground pools? Seems a 1hp pump should perform the same on either pool. His pump is also a lot louder than mine. Mine is quiet and smooth, his seems very loud. Thanks.

AG or IG makes no difference. Pump basket should fill with water. All your symptoms are indicative of low flow which could be due to several things. You really need to know the pressure and until you do we're guessing. Have you tried backwashing. Try switching to 'recirculate' or 'bypass' as that mode will bypass the filter. See what happens to the flow. Could also be crud that's tangled in the pumps impeller. Stuff can and does get past the basket and over time could get tangled in the impeller. Make sure the pump cannot come on and reach in through the inlet hole at the bottom of the inside of the pump basket and you can feel the impeller. You'll easily feel is anything is tangled in it. Should also be able to turn it with your finger(s). The pressure reading will give more clues if the problem is a suction side blockage. See how you make out with these suggestions and we'll go from there.
Al