G tec alpha 1 boi filter for sale big excellent koi pond filter I bought it for my set up but it’s to big where I want it to go on my set up I’m open to sensible offers & get bk what I paid works with k1 media will probably need more new media as I have about 10 liters of k1 new to go with it these are expensive filters if you google these you will see based in Warrington plz get in touch if interested thanks