Well, more Borax will raise your pH....no doubt.

My #1 priority would be to get that filter fixed. That'll do more to clear your pool than anything you can do right now.

In a working system, the filter will fill with water from the pump and any air in the filter will be pushed thru the return lines into the pool.

Do you have air in the filter or air in your pump basket?

Raising the pH to 8.0 get's close to a troublesome level. I have never heard of a floc needing high pH to perform it's function.

Sorry not to simply answer your question but it doesn't sound like you are fixing the correct issues.