After talking with an engineer of the air dome, which by the way is manufactured by Arizon not Horizon (sorry for misinformation) the problem with using bleach is there is no problem. The Rep I talked to before was worried about bleach deteriorating the stitching and I can understand that being possible. All the stitching is on the inside of the structure. On the out side the stitching is covered by a lap over seam that is glued making the structure water proof. The Arizon engineer said that my house wash mix would be ok to use. So I asked if he would call the owner and explain this to them and he did. Yesterday the owner called me to come down to demo our procedure for cleaning the dome. I sprayed my mix on just like washing a house and they were happy with the results. I start tomorrow morning cleaning the dome (providing the wind is not blowing to hard like today) which is 142' wide, 275' long and 34' tall. I will be using a 65' manlift to reach the top.