New Filter - Suggestions

[San O Fisher]

So despite having good water out of the tap where I am living now I have run into a bit of bad luck in the last few months.  First, after multiple healthy months of watching my discus grown I watched an entire tank but one get wipped out with a disease.
 
Now, my fluval 406 is having issues and sounding like there is something going on internally.  I have heard the loud noise may be due to trapped air, but I have tried everything to fix it and no dice.
 
My tank is a 92 gallon corner.
 
My options are
1. get another 406 to go along with the 306 that runs fine, but is old
2. I am leaning this way - move to the FX6
3. other options
 
any advice would be great as my goal is get this tank back stabalized, take my 12 day vacation in july and then add fish again.
 
Current stocking
1. Discus
15 rummy nose tetra
15 Cardinal Tetra
1 Snowball Pleco
10 sterbai cory

 

[Akasha72]

had to google this filter to check if it was internal or external. According to google it's external and so trapped air will always be an issue. I have two JBL externals on my 4ft tank and I have this issue with both of them - mostly after I've had to clean the pipes.
 
If it is trapped air you could try tilting the canister for side to side (evn give it a gentle shake too) this can help trapped air to dispel 
 
It's also a good idea to check the impeller for damage as this can cause noise too. If you really do think it's on it's way out and you want to replace - have a look at the JBL crystalprofi's .... as I already said, I've got two and I love em. They are super quiet, and super efficient (the e901 uses just 13 watts of power) and come with a 4 year guarentee which is not to be sniffed at!!