need some help and guidance

hi guys,

So i fired my local fish guy that was maintaining my tank. He came highly recommend, but with in the last 8 months my tank never really got going. he killed countless fish and everything else in my tank. so i bought a book and read up. i noticed a lot of differences between what he did and what the book says to do, Adding salt and other chefs- he just poured into the tank. :doh:

i have a 65 gallon tank.
about 80lbs of live rock
live sand
a 500 gph power head- just bought 2 800gph heads to replace the one in the tank
an ehiem 2217 cansister filter. Im currently sourcing the parts for a sump. i have a 20 gallon rectangular tank i will be using.
water heater set at 77

I've been cleaning and doing 20% water changes for 2 weeks now. 2x so far. tank has been set up and running for about 6 weeks.

saltinity is at 1.024
ph is 8.3
no3 is high 160
no2 is 0
alkalinity is a bit above 300

i have not cleaned the filter in over 2 years. my former fish guy was very adamant about not touching it. i looked at it and there are 2 sponges blue,white and some noodles in it. looks pretty nasty but it seems to work great. it clears the water in about 10 min after a water change.

I've read up and its seems to be recommended to clean them every month.

any tips would be great.

ps I'm currently recovering from surgery so i have not been at work in a month or so and another few weeks to go, so funds are kind of limited until i go back to work.