Question about filter/algae

I have been fighting algae for two weeks now. I have done some of the tips I have learned here. What I am noticing is that when I vacuum the blue liner, that the pump/filter discharge pipe pushes dark green water back into the pool. It is as if it is bypassing the sand all together. I suck it up, it goes right back in the pool. I have a Tagelus 60 filter, this is our first summer in this new house. I have never had a pool before.
I take my water to our local pool company for analyzation and chemical recommendations weekly. It seemed so clear for a long time with routine maintenance. Now, just green no matter what I do. No real changes, just more rain than usual. Could the filter be messing up? I took it all apart two days ago and inspected the inside. No visible problems noted. Sand looked fine (not that I know what to look for).
Thanks for any help,
Tony
20'x12'x 4'shallow and 8' deep custom vinyl liner pool in Louisiana.

Tony,
Welcome to the forum.
Don't know about that specific filter however, when you inspected it how far did you go? Removed the sand? Could be some damage to the laterals. These are basically slotted pipes in the bottom that keep sand from returning to the pool. On the outlet side of the filter. Is it possible the valve , whatever type it is, is set wrong and you're bypassing the filter? On a multi-port valve this would be Recirculate of Bypass. Would help if you could post some numbers for FC or TC (Free or Total Chlorine), pH, CH (Calcium Hardness), CYA (Cyanuric Acid or Stabilizer), and TA (Total Alkalinty). Best for now.
Al