I have a used Protien skimmer (unsure of brand or size if it matters). I was using the block that came in it for my first months cycle but then changed the block out. The block the store gave me is an "Ocean Foam" block and I had to dremel it down to fit in my tube. It's been running for about 4 days now and isn't making any foam. Do I need to trim it down more? The old one was making foam. No change were made to any of the set up at all. Any ideas? Thanks.