Issue with pump?

[daveyboy43]

I have a Hayward EC-45 earth filter. Since opening the pool a few days ago I can't maintain constant flow to the pool. Tonight after cleaning my filter fingers and then soaking them in muratic acid for several hours I put everything back together and added the appropriate amount of earth only to have the return flow get very low after a little over an hour. This is how it's been since we opened the pool. If you pump the filter or backwash it the flow is very strong for an hour or so then it gets very low. This evening I seemed to hear some type of rattling noise as well. Any help is greatly appreciated as we leave for vacation on Friday.

[Denniswiseman]

What are your numbers and how do you test
FC:
TC:
pH:
TA:
CH:
CYA:
You may have an algae bloom that is rapidly blocking your filter and may need to Slam