[PH problems with my new tank]

If you look in the sideways pict, the PH is 7.8 or higher.  Everyone is healthy.   My shrimp even shed after only two weeks in the tank.  My sword plants are lookin a bit sad.  I put in root tabs, a better light and I give the tank a bit of flourish weekly.  Am I missing something?

[PH problems with my new tank]

I haven't kept fish for a few years now.  I'm having an issue with my PH being too high.  My KH and GH are good, but my PH is off the chart!  I did a water change yesterday and I did one today too cause my KH went up too.  I think cause I used a bunch of that PH down stuff.  Well, PH down did NOT work for me..I put like 30 drops in over many hours and my PH is the same.  This change I used RO water My filter isn't that old.  I saw the review on this tank by co-op and will be changing out my filter to more substrate.  I have 4 guppies, two shrimp and a snail in my planted 5 gallon aquarium.  I'm starting to think the PH tester is wrong.  Oh, and I don't like the tester strips.  They are way different than what the kit says.  P.S.  I tried to get the picture to sit up straight... No bueno!