My cover is very tight right now. Tough to tell in the picture, but it's definitely pulled extremely tight. I could probably bounce a tennis ball off the cover it's so tight.
Couple of tips.
1) Make sure you blow the leaves off the cover on a regular basis. Otherwise they get wet and start to breakdown and decompose on the cover. I hit them with the backpack leafblower about once a week in Oct and Nov.
2) At the end of November, when all the leaves have stopped falling and blowing around, I dump 2 gallons of shock on top of the mesh cover. VERY IMPORTANT Then I loosen the clips, and unroll the extra slack in the cover so that the cover rests very... very....very loose on the rafts then reclip the cover in this loose state. For this very reason, I purchased a 28' mesh cover even though my pool is only 24'. You need extra slack in the cover during the snowfall months. It's important for the mesh cover to hang loose in the pool becaues the first heavy snowfall/snowmelt will tear the mesh cover if it's pulled too tight. The more rafts/inner tubes you have spread across you pool the better because they keep the cover elevated (even when the cover is loose) so that cover doesn't sag into the water. If the mesh cover sags into the water, the pool water from below will pass up through the cover and you'll never be able to pull it tight because they'll be too much water on the top. In addition, any leaves and debris will start to decompose in the water on top of the cover and will pass through the mesh cover making a mess of the water below the cover. That's why you see so many rafts under the cover in my picture above. Keeping the cover mesh cover elevated and suspended over the pool water (even when loose from Dec - Mar.) is they key to having clear water when you go to open the pool. Mesh covers are great....but you have to keep them clear of leaves and debris to prevent decomposing debris from passing into your pool water. In late March, I gradually pull the cover tight again (starting at one side of the pool moving my way around to the other side) and reclip all the edges. Once tight, I add 2 gallons of shock to the pool cover and wait until June to pull the cover and SLAM the pool.