Mahesh, do you have a sump ? If yes, get a Reactor and you can run Phosphate Absorber, the common types are either Iron base or Aluminium base. For iron base, common one will be either Rowaphos or AF Phosphate Minus. These are only to run with Reactor to get the true benefits. Rowaphos is used by more people I believe but becareful to wash it with RODI water before using, it tends to leak out brownish water during washing. For Aluminium base, I would recommend FM Ultraphos. This can either be run on Reactor or you just pack in a bag and throw inside the sump for it to works. This can also be placed inside HOB filter if you have no sump. The other similar to GFO option is using AIO Bio Pellets, this is carbon source combine with Some GFO, but this need a good Reactor to tumble the resin and it takes quite a while to run in. Hope these Info are good for your reference. Sent from my iPhone using Tapatalk