A bristlenose pleco or a farlowella would do well in 30 gal and pose no threat to your angelfish. The angelfish however will need a larger tank as they grow too large eventually for 30 gal.

 

a pleco will grow quite large too so u should only get one. And a larger tank is a must.

 

Bristlenose plecos rarely exceed five inches. Common plecos as stated grow large and would not be suitable for tanks smaller than 75 gal.;-)

 

If you're careful with the type of pleco they'll stay small. That said 95% of the plecos I see are just common plecos that can be tank busters.

I'll give my usual speech about controlling algae by identifying the causes and correcting those rather than relying on a fish to do it. Plecos will need some driftwood to gnaw on as they grow and there's a good chance that once you get them eating prepared food he'll ignore the algae. Then you're left with a pleco in your tank and you've still got algae. It might work out but the chances are good that in six months you'll be looking to sell someone a pleco and trying to find another way to fight the algae.

 

I ended up getting 2 Rubber mouth Plecos (rubber lipped?) I have heard they stay relatively small. Is that true?

All the Algae is gone lol

 

From what I've read it seems the average adult size is approx. 4".

 

just one thing you should know.... even with plecos....you wont see much of an algae problem change.

 

The following plecos that will do a nice job cleaning up the algae would be Sturisoma panamense, Ancistrus sp. and Panaque maccus. IMO, get nerite snails. These are better and smaller thus can effectively consume the algae. You will need to supplement them with vegetable matter and make sure your water is not acidic as this will cause shell erosion.