We are nearing the end of pool construction. Plastered pool 2 weeks ago. Pool builder has been relatively unavailable since plastering. And he is now on vacation. I'm having a multitude of issues. 1st problem:

Pool builder installed equipment, including pool pump (Intelliflo 4x160) & sand filter ( Pentair TA 60). We have been continually brushing the pool to remove dust; however, little to no dust is removed. In looking at installation it plumbing demonstrates:

Main drain & skimmers to Intelliflo input. Intelliflo output goes into a T. One portion of T goes through chlorine generator (IC-20) and then into pool returns (bypassing filter). Other portion of T goes through the filter. Filter output T's into pool returns, just prior to the chlorine generator. This makes no sense to me. It seems to me that only a portion of the water is being filtered in this scenario. Is there any scenario where such a plumbing setup would be desired? It would seem to me that the Intelliflo's output should go directly into the filter with no T. I asked the pool builder via phone. He mentioned something about the TA 60 not being able to handle the full flow from the pump when pump is in highest speed. TA 60 is showing a pressure of around 4 PSI (seems low to me). After many days of trying to brush plaster dust into the main drains, there is still a ton of plaster dust in pool. Additionally, filter PSI remains unchanged. I think the majority of plaster dust pulled by the main drains is bypassing the filter due to plumbing and being redeposited into the pool. Can anyone shed some light as to how the TA 60 & Intelliflo should be plumbed together?

If need be, I can diagram the current pool plumbing and attach. Thanks in advance for the help.
Chad