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Old lights causing algae?

1902 Views 13 Replies 6 Participants Last post by  bsmith
About 6 months ago I set up my aquarium again after a 2 year "break". So far I have just been using my old lights that were stored for the 2 years. Before that they were only used for a few months. I have been battling the algae for the entire six months with no luck. It is getting critical and if I don't get this taken care of it may mean goodbye to my planted tank. Oh the algae is green thread algae...I think.

Specs: 37 gal
Lighting: 2 x 55 watts
CO2: Pressurized 20-30 ppm
Ferts: EI method
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It's not the lights. You may have them on too long. That is high light. Reduce your photo period to 7 hours. Get some amano shrimp, black mollies, etc. They will eat it. Try dosing with excell and see if it responds. Some of the green thread it will kill.
Thanks for the tip. I dropped the lights down to about 8 hours a couple days ago while doing a water change and it seems like it has helped. There is still some stiff algae growing on some driftwood that my SAEs won't touch. My amanos aren't touching it either. Another question. Could old dry ferts cause algae? I am currently dosing some dry ferts with the EI method but they are about 4 years old. Is it time to purchase new ferts?
Ferts are okay aslong as they havent been exposed to too much moisture.
Ya, I didn't think it would be the fertilizers. I may have just figured out my problem them. I have gone through so many options and scenarios that I feel like a detective. Anyway, I have been using water from our kitchen faucet for water changes, the only faucet in the house that isn't hooked up to our water softener. Anyways, it is freezing here and the tap water is about 55 degress and I've been using the hot water to bring the water to room temp quicker. Well, the water heater comes AFTER the water softener and I've been getting all those wonderful chemicals and such that come from the softening salt. Does this make any sense? Could the water from a water softener cause algae?
Not likely. Softening systems just add salt - which isn't really good for freshwater plants or freshwater algae.

The likely causes are as Tex_Gal said - lights on for too long and a nutrient imbalance. What are your nutrient levels.

I am willing to bet that your nitrogen levels are off.
I'm fairly sure it's not the lights, I lowered them down to 8 hrs from 10. Not a lot for the just under 3 wpg that I have. I've also been dosing Potassium Nitrate in the EI method. I dose KNO3, Plantex, and monopotassium phosphate 3 times weekly with a weekly water change.
another thing to look at is plant load. if your tank is sparsely planted, you would have lots of nutrients floating about, that would be taken up by algae.

if you don't have a heavy plant load, i would look into adding some fast growers, to help offset the amount of nutrients available for algae.
Good thought. I'd say that it is moderately planted. Here is my dosing schedule. Does this look right?
1/4 teaspoon KNO3 3x Weekly
1/16 tsp. Plantex CSM+B 3x
1/16 monopotassium phosphate 3x

plus 50% water change once a week.
Looks ok. Can you do some water tests to see what the nutrient levels are?
Forget the black mollies there ugly as, with high light like yours over 3wpg you must be getting low on no3. your only adding 5 ppm each does it might be running out? I would invest in a nitrate test kit. i was getting thread algae before i up the kno3.
Good observation. A lot of people have noticed that thread algae tends to disappear when the nitrates are increased.
I'll measure it today. I already have a nitrate test kit. Perhaps I need to dose every other day. I'll let you all know what the test reads. Possible this can help someone else in the future.
I had an algea breakout when my pc's when bad (a little over a year old). My plants started struggling, and when plants struggle you know what happens... Algea. Im not saying that it is the cause of your problems, as others have stated your Nitrates seem like they might be low but if I were You I would get some new bulbs. Now I replace mine every 9 months or so. ;)
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