I have been diving for a while now and I have been thinking to go over to diving doubles. I have a few single scuba tanks, but only 2 10L 300bar tanks that are identical. So I was thinking to buy new valves and tank bands to convert those to doubles. I didn't want to buy a new set of tanks mainly because of the price, as I live in norway and a new set of D12 is around 9000 NOK, but a conversion kit is around 4000 NOK, but also i felt like my single tanks would go to waste just sitting there. I was wandering what some of the issues or considerations there are when converting singles to doubles? I have heard that a lot of people don't like twin 10L 300bar tanks because of their bouyancy and trim characterisitics, but is it really that bad?