ok i have just read about sumps and i would like to have one but i dont know what i need. can some one give me a list to buy for a sump in a juwel rio 125

thank you
When you get the Juwel Rio 125, measure the inside of the cabinet. If there is a centre support behind the two doors, this will need to be removed and then an "n" shaped wooden reinforcing structure should be put in place to support the tank. If there is no centre support, then ignore the above and just measure the inside of the cabinet.
Since my old Juwel Rio 180 could only just house a 2ft and hob skimmer, I'm assuming you will be looking at probably a standard 18" long tank. You may be lucky and still fit a 2ft tank in there, as I had to use a reinforcing structure which reduced the amount of space I had inside the cabinet.
Apart from the tank, you will need glass baffles cut to size. You could actually get away with using acrylic and siliconing it in place. Although silicone doesn't form a strong bond with acrylic, it should be sufficient to hold baffles in place.
The other thing you will need to do is either get your tank drilled or use an overflow box. Personally, I would get the tank drilled. Its a lot safer in the long run. You could use an overflow box but, they do require the air syphoning out of them from time to time. Have a read up on Melevsreef.com. There is lots of information on sump design, overflow boxes, weirs, etc, etc.
You can also save yourself £30 and look on ebay for vibration water pumps. You will find powerheads that are identical to the Koralias for £16 with free shipping. Look for the 3000 LPH one's. For £22 you can get a dual one which shifts 6000LPH.
I'd also look on ebay for your protein skimmer too. You will be able to pick up a V2 skimmer or another decent make, used, but at a decent price. So long as its in good working order, its well worth doing. I picked up a £230 skimmer for £70. I paid another £15 for a replacement impeller. Good as new!
I'd also recommend that you look on ebay for people selling live rock locally. People often close down their tanks and sell the rock for significantly less than what your LFS would charge. Mine were charging £13 a kilo the last time I looked.
I also tend to find that ebay is the cheapest place for the test kits as well.