Gobies or blennies? (Long list of questions)

[Claw Atticas]

I was thinking of getting those fish that eat up sand and sift it through their gills (I always enjoyed watching them in the fish store and aquariums around here), but I have a few questions:
1) Should I get a goby or blenny? And which kind is the best?
2) Goes with 1, but which causes the least amount of trouble? I've heard some will dig out sand from under the live rocks
3) Will they be hurt by eating cyanobacteria or diatoms?
4) I saw that blennies are herbivores, would they help me with my hair algae problem?
5) And most importantly, would any of them have any troubles with my other inhabitants?

44Gal saltwater
pH 8.3
Salinity 1.026
Ammonia 0
Nitrates 0
Nitrites 0
Calcium 450
Temp 78
Phosphates 0.5

Current inhabitants:
1 Firefish
1 Ocellaris Clownfish
1 Coral Beauty Angelfish
1 Longnose Hawkfish
Xenia Coral
Galaxea Coral
1 Emerald Mithrax Crab
15 Nassarius Snails
15 Astrea Snails
1 Mexican Turbo Snail

 

[Ziggy953]

If you are having issues with hair algae and cyano bacteria you need to figure the source out for those problems. The sand sifting gobies will work on the sand but usually in one specific area. They are territorial and will stick close to home. I would not suggest getting a blenny to deal with the hair algae. A reading of phosphates says that you have too much in your system. You may want to run a phosphate sponge or some other phosphate export method. Test your source water for phosphates.

What kind of food are you feeding and how much? what kind of filtration do you have in the tank?

 

[melosu58]

I agree that it looks like your phosphates are the answer.