Algae is making me cry.

[Heady]

I have lots of green algae growing on sides of tank and even on the onyx sand substrate. I've tried blackouts, after which I have about a week of no algae. I've tried "algae destroyer" liquid, which does absolutely nothing (I've given up on it). After blackout, I've tried only turning on half the lights. What the heck is going on?

Tank Stats:
100g acrylic tank
4x55W compact fluorescent lighting, limited to 10 hours max
Two filters: Eheim 2028 and Eheim 2213, disassembled and cleaned every 3 months
Two heaters
50% water changes once a month
Fish fed once every other day
Fish: 10 cardinals, 1 upside-down cat, 2 cories, 2 pearl gouramis, 1 betta, and 2 kuhli loaches
Heavily planted several times a year, most plants die quickly.
Ammonia and Nitrites are at 0. (I don't have a nitrate test kit.)

This tank was so beautiful when it was first set up. Now it makes me cry. Ideas??

 

[jamjarjames]

my guess is that your nitrates are through the roof supporting the growth of algae

I say this because your not carrying out water changes often enough. Idealy water changes should be done on a weekly basis changine 25%-50% a time.

This will dilute the nitrate and stunt the grwoth of algae

 

[fishlvr]

I gotta agree here... I used to neglect my tank of regular water changes and always had algae growing just about gravel level all the way around the tank. I had my water tested and nitrates were 200ppm+

after regular, weekly water changes the algae is gone and hasnt returned. 25% weekly water changes will do wonders... go ahead, try it out

 

[RobUK]

Also established plants will out compete the algae for nutirents so it wont grow as much.
But as you said you dont have alot of luck with plants, Welcome to the club. I hate fake plants allmost as much as I hate my withered looking live plants

 

[wetmanNY]

Which kind of algae is it, Heady? Are you in Pacific Northwest soft water? or hard water?

 

[anonapersona]

OT- WetmanNY, good to see you!

Sorry to hijack the thread, but hey man, it is good to see you around again! Long time no see.

 

[Hans]

check your phosphates

 

[cdawson]

no it's definately too many nitrates, 50% water changes on a large tank like that should happen every week, not every month. Not only that, your plants will appreciate some of the minerals and junk that come with your tap water. also, how are you cleaning your filters? You shouldn't be cleaning them in tap water, make sure you clean them in old tank water (after a water change).

Your plants should not have to replaced several times a year, I would check the ph of your tap water or your choice in plants. Most plants are pretty hard to kill, if you're killing plants that often then something is really wrong.