We are putting a 1000 litre tank in the ground at a mates place and I'm wondering if anybody has any idea what type of fill is best to put around the tank to hold it in the ground. The tank is shaped like a hand grenade so we have to be careful with what we put in there because the shape might help force the tank up and that is something I couldn't face again because this tank has caused us massive issued with it popping up and breaking the pipework because of the amount of rain we have had since the hole was originally started back in May. This week is the only time we have had where we can see we have a number of days in a row where it is not going to rain. We got the tank back in the ground yesterday and got it piped up. We have hammered 4 star pickets down into the subsoil a meter and 2 chains with turnbuckles over the tank to hold it in place while we put whatever fill around the tank. We have considered concrete but it might try forcing the tank up. Googling it they suggest using cement powder and crusher dust compact just 75 to 100 mm at a time. I am not sure what the mean by this because the mini mix is just going to dump this in the hole. Any thoughts welcome.
