Thanks for the advice Rubbin. Initially that was the plan but once I got the legs on I found that its surprisingly rigid. Once its bolted on to the trailer (with its added supports) it should hopefully be fine. But we will see once its on there. I understand the need for the x-braces but I'd like to keep the weight as low as possible. If extra support is needed I was thinking of adding another leg on each pair. This would go from the bottom plate on the legs at an angle to the bottom of the tank. This should help strengthen from horizontal forces applied by breaking if necessary and keep down weight.