Just the strength, but here's the catch.
Often, when you find "liquid Shock" or Chlorine at hardware stores/big box hardware stores, it's been there a long time and is weaker. It starts out 10%, but by the time it sits for months, it's weaker. Maybe 6% or less. So, people like me who want it, usually buy store brand bleach in the laundry sections where ever it moves quickly.
It sounds like you may have some filter issues then as well, so I would replace that spider gasket to eliminate that potential problem. Just stick with it, rain or shine, and you'll get through. You might run a CH on the pool for grins and see how much your CH has risen, but you may not have much with all the rain and BW you've done. If you start humping bleach for this, just remember that you won't need too much once this is all done. when that time comes... Stock up on several bottles and then pick up what you need at the store each week, and it's pretty easy that way. Even in my pool at 28K gallons, it isn't much hassle.
