With diatoms and dino I have had good success by removing silicates and phosphates from the water column. I think GFO will do the trick but read the label first to make sure it will pull the silicates out. This will get them out of you display unless you reintroduce them. If you start seeing them again after you have gotten rid of them, you are somehow adding the silicates back into your system somehow. I would then check your water filter or possibly your salt.