Diatoms...problem just won't go away.

[Snufflupagus]

Hey all,

Well I've had a diatoms problem for months now and just getting tired of dealing and looking at the stuff. Recommendations I've been told to do were:
More water changes, syphoning it out. I've been doing both religiously and the problem just won't stop. There are times that it looks like it's getting better, then a couple days later will be back in full force. Hoping someone can help me come up with an idea on how to rid this pain in the ars stuff.
Tank is 150gallons (roughly 180 total volume with sump) I'm running GFO and bio pellets (note that I'm running 1.5 cups of GFO and 2 cups of bio pellets, I'm suppose to be running 4 cups of bio pellets, but am taking it slow in getting the total amount up) I have a high bio load, but my skimmer seems to be doing a good job as I empty the cup every 2 days and it's full with good brown sludge. Flow in the tank is setup to hit all areas in the tanks so there are no dead spots.
I started to dose zeostart, zeobak and coral snow to see if this helps the problem, but I don't see any difference.
Other things I've been told to try and/or not do:
Buy some probiotic products and dose them.
Stop the biopellets
Do not stir up the sand bed

All my fish are happy and my sps and ops coral growth has never been better, they seem to be very happy. I have multiple crabs and snails in the tank for a clean up crew. I also have a sand sifting star and sand dollar in my tank.

I just got new AI LED lights (put them up yesterday) and have them running at 30% right now, at it's peak time.

My sand bed is 3" in some spots and as low as cm's in others.

I did start the tank using 60% new rock and the other 40% was from the tank I shut down. I know the problem is probably due to the newer rock, but the rock has been in e tank for a year (roughly) now.

I'll keep battling the problem, but thought I'd ask the pros if they have any other ideas on what I could be doing. Help is appreciated.

Thanks,