first large AG batch

I did a small stovetop AG batch when I first started but I am now setup and doing a 4-5 gallon batch. I'm fermenting in 5 gallon buckets so closer to 4 gallon to leave head room. I'm finishing up my mash, so far so good, and getting ready to boil. iodine test looked good so I'm thinking I have good conversion, although I'm color blind so I'm half guessing that it didn't change.. lol. Anyone know a non color dependent conversion test?

So I'm noticing a fair amount of grain particles in my wort. I have a plastic false bottom with about 1/8 inch holes. I've been thinking of converting this to a stainless braid type system. Is it normal to get some grain particles in the wort? Will it cause any problems?

you want to vorlauf until the wort runs clear before siphoning into the boil kettle.
By recirculating back(vorlauf) on top of the grainbed the bed acts as its own filter which will allow the wort to run clear(no bits of grain)

Did you make your own mash screen, or was it store bought?

If you have some sort of paint filter bag or kitchen strainer, I'd pour the wort through that before boiling the wort with all the particles in it.

I bought it from someone else so I don't really know if it was store bought or not. I did the vorlauf and it did get alot clearer but there was still some particles. Not husks really but particles.. if that makes any sense. Also my gravity came up lower than I expected. I mashed 10 LB of 6 row and 1 LB of crystal malt in about 3 gallons of water at around 154 for an hour. I then sparged with about 3 gallons at 170. My total after boil volume was 4 gallons and my OG was 1.042. I really expected this to be higher. Am I wrong in that expectation? Should I be using more grain? I did an iodine conversion test and believed it was complete.