My tent is saggy / baggy which allows water to pool. How can I fix this?
"To create even tension on the tent, all the adjustable tension straps should be fully loosened before you pitch the tent. Loosely secure one corner of the tent to prevent it being caught by any breeze and erect into shape.  Once the poles are erect working from front to back pull the tent tight and securely peg down. Once pegged down work your way around the tent applying a small amount of tension to the adjustable straps until even tension and an even gap is achieved.  Finally, peg the guylines out at right angles to the tent. On tunnel tents, the guylines on the front and rear poles, should be pegged at an angle towards the front and back of the tent, as this will help to create tension along the roof panels.

In warm dry weather the material will contract and become tighter. As such the tension straps will need to be loosened to release pressure on the poles. Similarly in wet damp weather the material will expand and as such will require further tension adjustment until the material drys."