Question: Skimmers and Tank Capacity

Hello,

I am presently starting a 220 gallons reef tank.

The sand and live rock, etc. will take about half the available space inside the tank, which means the actual water quantity in the tank will be about 100-125 gallons.

My question is : when I buy a skimmer, do I take into account the capacity of the empty tank (220 gallons) or the actual water qiantity in the tank (100-125 gallons) ?

I want a hang-on configration. Any skimmer to suggest ?

Thanks to all who will answer.

It has been my expierience that 'most' skimmers say they are rated for XXX Gallons and they are only good for XX gallons. IMO get a skimmer rated for like 350-500 gallons. I hear the MY REEF skimmers are actually rated correctly. in that case or another brand that is rated honestly get the skimmer to handle your Whole tank capacity including sump volume (which it sounds like you aren't going to have). In the case of hang on's available I'm not sure but I have never seen just one that can handle that size of tank. I have a Red Sea Berlin hang on and I believe it is 'rated' for 125-250 gallons I use it on a 35 Gal tank and I believe it to be good for tanks 70 Gal and under. the truth about skimmers is unless you can build a good one you get what you pay for. Spend the dough now on a ETSS or a MY REEF now and avoid paying through the nose on upgrades later. These are all opinions and should not be tried at home without parental supervision HTH, Toy