Time for measurements, new liner, etc

Hello all, happy 2013... time for a new liner and first time starting from scratch with new water.

I didn't get my measurements done before it got cold and now the water is green heh. Just hit it with bleach trying to get it at least back to somewhat clear even though it's going to be drained.

Some questions:
1. Any recommendations for one of the more reputable places to order a liner from?
2. If I drain the pool to do the measurements, am I going to need to refill it temporarily or can it stay empty/low?
3. Exactly how accurate do you have to be on the measurements? It seems like a pretty exact science. My pool has 45 degree corners.
4. Our pool already gets very warm in the summer with a light colored liner. Would it be much worse with a darker liner or negligible?
5. Is it worth it to get one of the thicker mil liners or do they all last about the same?
6. Is it possible to change the light and light socket while doing this upgrade or are you pretty much stuck with what is in there? (does it require access to the back side of the wall, which is under concrete)
7. The filter sand has gone through 4 seasons. If I decide to change it should I do it now so I can flush the fine sediment out or should I just do it later? I hate thinking about all the crud in the filter that I would be introducing back into a pool full of fresh water.

Thanks for any input!
-stephen

#2: Depending on your water table, leaving a pool empty is very risky. I would not leave it empty any longer than you absolutely have to. The weight of the water helps keep it in the ground and not floating.

#4: It would be significantly warmer with darker color. Check out pooldoc's recent post here: http://www.poolforum.com/pf2/showthr...856#post104856 Although he was talking about paint, the effect should be the same with a colored liner.

#6: If the niche is under concrete, you probably aren't going to be changing it without busting the concrete up. You should be able to replace the light and use the existing niche without a problem, though.

#7: My understanding is that you never really need to change the sand media. You can if you want, but bleach and a backwash with clean water should do the needful too. If you decide you want to change it, do it whenever suits you best.

When you're filling the newly lined pool, get chlorine in it asap so you don't fall behind. Be sure to use really small doses and test often while filling so you don't bleach out the new liner if you choose something other than white.

Thanks for the input. I'm really concerned about the measuring since you cant get a quote without the measurements and each dealer has a different form and asks for a few different things. Of course I want a good liner and a good deal! Hard to get much price match without using a few versions of the form!