Short and fast answer yes after several years of non-testing and water changes only, I have developed some pretty high phosphate test kit results. Odd thing is that I do not have in anyway shape or form have an algae issue of any kind. I also have excellent growth and polyp extension on everything (sps, lps and zoas). Really its very odd because you would never guess they are as high as the repeated test kit said if you looked at my tank.
Anyway I am guessing that the phosphates are a combination result of not running a skimmer (or any other phosphate control methods aside from cheato), zero open sand bed and possibly heavy feeding NFS pellets. Anyway I would like to get these down to a normal range and have determined (still open for different suggestions and or methods) that GFO is my best methods of lowering.
Picture of my tank just a few days ago.