algae arguement?

[ewok]

after an earlier post i'm sitting here thinking about algae...

almost the first question/suggestion in almost any case of algae has to do with light. even i do it.

why?

from what i can think of light really isn't an issue in most of the posts i see........ i'm beginning to even wonder if light is a myth that we keep propagating.

i know all plants need light and making the tank dark will help control green water.

but as to actually causing the algae problems? i'm seriously beginning to doubt.......

i have done some crazy things with my tanks in the past, and even now i stretch the limits. i have a 29g in front of a window that's overstocked, overfed, and has the lights on WAY too much according to a recommended cycle. shouldn't i be over-run? granted, it is currently winter light which isn't as bright as summer. but there is NO algae eater in the tank to speak of. the only thing between that tank and being totally exposed is the plastic background and the light goes right thru that. not to mention the light gets a straight shot at the side of the tank, it is offset from the window slightly........ shouldn't this tank be green soup?

tank 2....... my 55g that i breed convicts in, i had a couple predatory cats in there at the same time and to ease the effects of those cats on my fry........ i left the tank lights on for probably a month and a half straight, until the fry were old enuf to be removed safely. that tank *also* gets some indirect lighting in the room. it only has 1 algae eater, l001 pleco.... but for most of the time i had the lights on, there wasn't one. shouldn't i have some serious foliage growing now?

tank 3 ........ an old experiment. everyone always talks about green water and i had never seen it. so in a 10g with a couple guppies i was trying to breed i decided i wanted it. same thing, i determined to leave the light on until it happened. again, the lights were on like a month and a half straight and i *still* had to screw up the cycle to cause it to happen........

my only conclusion here is that light actually has very little to do with algae. poor maintenance and way too many nutrients seem like a much more viable source........

points to ponder............ :confused:

anyone care to comment?

edit: just for reference, these tanks all have standard flourescent bulbs. single tube, aqua*glo, watts are normal for the tube sizes. the tube in the 55g convict tank is even over a year old....... isn't that supposed to promote algae too?

[OrionGirl]

Yes and no. Light is but one aspect of algae growth, and seldom the most important. For most situations I've heard of, the biggest contributor to algae problems is over feeding. This does 2 things--one, provides lots of ammonia/nitrates. Two, contributes a significant amount of phosphates. Of these two, the phosphates are normaly a bigger factor, IMO. The ammonia can be dealth with bacterially, while the phosphates just keep piling up. I think that chemical manipulations gone awry--such as pH modifiers used heavily in low buffer water--contribute significantly to algae nutrients.

I think the tank occupants play a significant role as well. Many fish feed on the little critters that feed on algae, allowing the algae to gain the upper hand. In tanks that have mostly large predators, the microfauna can really help out in controlling algae.

The type of algae is also important. I have tanks with 3 kinds of algae, in small amounts, one with basically no algae, one with a bit of soft green algae, and one with a touch of cyano. The only tank I make any reduction effort in is the one with cyano--that stuff is pervasive, and smelly. I clean off the glass in all my tanks, and pull out a bit of the hair algae--it's never spread off of one log, so I just keep it trimmed, like I do with java moss. It seems that some people over react to a bit of algae--adding more fish (unlikely to help), or worse, treating chemcially, disrupting the stability of the tank far more than a tad of algae.

[ewok]

good point with the microfauna.... but wouldn't the fry browse these?

i'm starting to wonder about phosphates tho, might be time to invest in a test for some experiments. i have been blessed with low buffer, neutral water and i stopped adding anything but water and food awhile back. *except* stress-coat for water changes....... doesn't that add phosphates?

everything else is sort of scattered tho. most of my tanks have emperors, but not all and only 2 out of the 3 tanks mentioned also have an air source........

oddly enuf the 29g only seems to get a little on the glass that i mostly clean with a magnet.... the pvc pipes and the black glass just show a little brown and i'm sure otos would adore it, but the oscar in there in quarantine would adore the otos as a snack. ;)

[TKOS]

I sort of assume taht most people overfeed their tanks, thus light is sort of the next step if the nutrients are already there. With no light adjustment I can control my algae with extra water changes so I assume I am over feeding my fish.

[OrionGirl]

Most fry will consume microfauna--but seldom in sufficient quantity to deplete the tank, IMO. Plus, most fry tanks get more-than-usual water changes, so the other components are likely reduced.

I think something else that needs to be considered is how you define an algae problem. I think some people stress if there is even a touch of algae, while others are not so concerned about it. I cleaned the glass on my tanks for the first time in over a month--none of them were really bad, just a few hazy patches. I never wholesale remove algae from rocks and wood, and just snip off a leaf that gets covered with algae (other than brown--I can't recall the last time I had brown algae, though). I do know of people who feel compelled to erradicate any tiny amount of algae that may show up, though.

[125gJoe]

I found this article to be interesting:

http://www.hallman.org/plant/algae.html