Ok! So while my title says it's a new tank, it's totally cycled and has been for months.
Now, I will admit I made the mistake of placing this tank right next to my dining room window so I ended up with ALGAE! But the tank wasn't too cloudy. We moved the tank further away from the window (still in the eat-in kitchen but not right in front of the window), but that didn't seem to help. Then my filter DIED. Flat out DIED. I HAD no choice but to run out and get a whole new one. Then the cloudiness got WAY worse. I figured AH the tank is recycling so I didn't pay it too much mind. Water values were all fair (not great, but not bad). Well, the heater then decided to BREAK (it was an old heater, should've known better)! Well, my water turned VERY cloudy and most of my fish DIED. WELL, I did about 3 water changes over 5 days (the first one was 75%, the rest about 50%). My pH was OUT OF CONTROL, reading 6 (I think it was worse) for a week; I went thru AN ENTIRE BOTTLE of pH up.......which brought the readings to 6.4. LONG STORY SHORT, the pH is finally at 6.8 (although would prefer 7.2...slowly getting there), ammonia was up to 1 but is back to 0, nitrites 0, nitrates 5. I have 2 albino corys, 1 upside down cat, 1 mickey mouse platy, 2 sunburst platys, 1 "odd ball" platy, and 2 fry (found them amongst the muck!). I also have 2 "large algae shrimp"--they just look like really big glass shrimp, 2 mystery snails and 2 gold incas (and 2 large egg packets). I have real plants and real driftwood.
Here are the chemicals/things I have tried so far:
1. Accu-clear by API...did absolutely nothing.
2. Activated carbon...did absoultely nothing
3. Added an extra filter pad thingie I had to cut on my own...did absolutely nothing
4. pH up
5. AmQuel
6. pH stabilizing tabs
7. Kent freshwater clear...did NOTHING after 2 doses.....
I'm at a loss. Seriously. I had big plans for this tank. I'm so disappointed, I spent SOOO much money.....I was going to do yet another water change but I figure I'd ask here first on what to do next....and I doubt it's water hardness issues as I had no problems when I had my 10 gallon and used the same water.......I just didn;t think it'd be so long, I can't enjoy my tank, and I'm not enjoying the experience

My water has been awful now for 7weeks (it's been 4 weeks since I moved the tank from the window).
HELP! What else can I try?!? And should I do another water change?!?