Can I suggest a method of development that APUG members may agree or dissagree and if so, suggest a better method for development of 35mm film? The method I use (assuming you are using dev at 1:1) is one I picked up some years ago and although I once used water jackets and such like, but assuming youre using tap water as part of your developing solution and not distilled or deionized water, this method is fairly easy. To make a 1:1 developing solution for one 35mm film, you will need 150ml of water mixed with 150ml of developer = 300ml (I know it says 290ml on the tank, but 300ml and its division by ½ to 150ml is easier to remember). This mixture of developer and water should ideally be at a temperature of 68F/20C. Pour 150ml of developer into a measuring jug and measure its temperature. If it is under or over 68F/20C, make a separate jug of water to compensate for the difference. Example if the developer temperature is 18C, make the water to 22C, before adding 150ml of water to the developer. To get the water at the required temperature, put a thermometer in the empty jug and add hot and cold, either from two separate taps or a mixer tap. Dont worry about the quantity as you can let the excess flow over the edge, just concentrate on getting the temperature differential you require. Then pour out the excess to leave 150ml and add to the developer in the separate jug. Thus, you have 300ml of developing solution at 68F/20C.