Hi Guys and Gals, First time i will be putting sealant in my mtb tyres, took it to cycle lab and got it back with flat tyres. It had Stans in it before i took it to them ( not impressed as you can tell). So i need some guidance please; - Can i use a different type of sealant, Ryders? - Is there a trick to this? Do i do it from flat or from with air in them? Any help or guidance would be much appreciated.