algae in nature question

[new2scrub]

when you clean a scrubber you are removing the algae just before it dies or it's growth slows, thus you remove N,P,and other nasty"s like metals witch have all become part of the algae. But in nature nobody removes the algae,,,yea snails and other herbavours might eat said algae and some algae might simply die off and fall to the sea/lake bottom but the N,P,and others never are removed from the body of water. ? correct? how does algae work in nature? What uses the N and P up in the end of the cycle in the lakes and oceans?

[SantaMonica]

Phytoplankton does most of the filtering of all water on the Earth.

But on reefs in less that 100 feet of water, solid algae algae actually does most of the filtering; it is then eaten by herbivores (tangs, etc.)

[new2scrub]

ok but after the tangs and such eat the algae they then poop it out and that poop has N & P in it right? Does the next algae plant just start growing thus keeping that N and P forever locked up? Or does something else happen? If snails and tangs do NOT "poop" out any N or P well then it might make sense to keep a few snails in you scrubber box to remove algae 24/7 no?

[SantaMonica]

Each animal takes about 10 percent of the carbon value out of the algae. So a tang eats, absorbs about 10 percent of the carbon value of the algae, and poops out 90 percent. This is then eaten by filter feeders, inverts, small fish, etc, which take out another 10 percent of the carbon, leaving 80 percent. Then their poop (including from corals), leaves only 70 percent. After the last one in the line, the bacteria, there is no more carbon left and you have only inorganics: Ammonia/Ammonium. CUC's do not remove N and P; they just break down the big pieces into little pieces or dust, so that corals can consume it.

See this video here:

http://www.youtube.com/watch?v=pQaE0e0iD3s

[new2scrub]

wow good vids thanks for that! hey santa why does it always seem that my freshwater scrubbers take 3 times as long to start growing algae than their salty counterparts?

[SantaMonica]

They don't.