New Homeowner, a few questions

[sunlove]

You need to get a good test kit and test your CYA (Stabilizer) level. The stabilizer is what keeps the chlorine "stable" and the sun may be depleting it faster than you can add it if there is no/little stablizer in pool water. See the "best guess chlorine chart". http://www.poolsolutions.com/gd/best...ine-chart.html Once you have appropriate stabliizer, you don't have to worry about chlorine level jumping around.

I don't have a DE filter so can't answer you there. But how is the flow coming out of the return jet? I know with sand and cartridge if the flow is weak and pressure raises it is time to backwash or clean filter media. Have you done that?

About the vacuum, it would depend on how the flow is on your filter. If your filter is dirty or not working properly then vacuum is not going to be effective. You don't necessarily "need" something better you just need to get the filter situation figured out and it will work just fine just might be a little tedious for some folks Hope this helps.

[BigDave]

It'd be helpful to know more about the pool.
Remember to replace DE when you backflush a DE filter.
sunlove's advice is solid - about the vacuum, the testkit and the CYA. A Taylor K-2006 will be your best pool spend. Find 'em here: How to Get the Right Testkits for your Pool. If you buy through the links, the PoolForum get some cash to keep the lights on.
I think you may have the beginnings of an algae boom - the presence of CC, the FC consumption and the fact the DE filter is clogging quickly are indicators.We'll have a better picture after you can give us chemistry results from your K-2006.