The pleco's, namely the common ones or larger ones tend not to fair well since they will damage plants.
Some smaller types, the Bulldog pleco, , Clown pleco, the Butterfly, or the white spot Ancistrus(most Ancistrus generally are good or Pecklotia) are all pretty good.
But for algae over all, a large pack of amano's is difficult to beat and you can add any number to about any sized tank since each critter is a small algae eating unit.
Barbs are good for hair algae, mollies are okay for some algae, not a lot IMO,
Otto's are good for Diatoms and little else, SAE's are good for BBA and Oedogonium, it grows only on the leaf margins about 1/4"-1" long. I've seen them eat other algae but these are ones they seem to be effective agaist.
While having algae eaters is important, it is not the overiding critical factor. If you are slightly off in your routine, they may help sway the balance over to the plants. They will never hurt the balance. They will make a good balance even more stable.
But don't depend on them to make your plants grow. They cannot do that except through some waste products and then that generally does not amount to a great of plant nutrition unless the tank has very slow growing plants/non CO2 enriched etc.
If the tank has pretty bad algae, don't expect them to remove it all. You need to help that along.
Many folks seem to think algae eaters will solve all the algae issues. They do not.
Don't try one single method/nutrient etc to get ahead of algae and grow plants, try multiple approachs, like good nutrients for the plants, manual removal of algae, trim off the algae that's attached etc, clean filters, scrub glass, large regular water changes, herbivores in large numbers, etc. Repeat.
Take care of the CO2/Nutrients _and_ add the algae eaters.
It's easy to add the nutrients/CO2, it's very laborious to pick and trim off algae. So have the herbivores do that, and you follow up with good nutrients/CO2.
Trim well to get the tank as free of algae as you can first, then add herbivores and good plant nutrients/CO2 and have lots of plants.
This takes about about 2-4 times of trimming good and lots of work , then you an rely on the herbivore to do the work afterwards.
Whether you 20% or 50% water change a week, it takes almost the same time. I've always held that large frequent water changes is good. Especially when algae is an issue.
Some tanks are well balanced and folks can get away with less %.
I've been able to do it, but my plants do grow better and I do not have to rely on testing at all in order to hit the ranges I need for good plant growth.
Most have cheapy test kits so this method seems to be better than those in many cases..
I reset the tank each time I do a water change with the proper nutrient levels. I can get to within 1ppm of NO3, 1-2ppm of K, .3ppm of PO4 of my estimation.
Regards,
Tom Barr
