fish foods that don't add, or add minimal amounts of phosphates?

[6Speed]

I was wondering if there is a difference between the brands of fish food and phosphates?

[fsn77]

Yes, there is a difference. Reading labels is the best way to tell.
Here's some examples from dry foods I have for our tanks (mostly fw, but I'd be surprised if other sw foods are drastically lower)...
Hagen NutraFin Max Marine Complete Sinking Morsels: Min. phosphorus = 0.6%; Max. = 0.9%
Hagen NutraFin Max Cichlid Spirulina Sticks: same as Marine Complete
Tetra Tropical Crisps: Min. phosphorus = 1.2%
Tetra ColorBits Tropical Granules: Min. phosphorus = 1.5%
Marineland Bio-Blend Herbivore Formula: Min. phosphorus = 0.9%
Marineland Bio-Blend Bottom Feeder Formula: Min. phosphorus = 0.8%

The key point is that the Hagen brand foods have a max. phosphorus content that is lower (or essentially so) than the other two brands min phosphorus. I don't know if there are other brands out there that are lower in phosphorus content, but this is at least one example of the difference.