How to control algae in a low light tank?

[conny1908]

Hi everybody

I set up my first planted tank - a 46g bowfront - a few weeks ago. Lighting is low: 2 W/g. I leave it on for 12 hours/day.

The tank is filtered by a Filstar xP2 and has a 14" bubble wand for added surface agitation at night.

I ordered an assortment of low-light plants from FloridaDriftwood. I couldn't identify all they sent me because the plants weren't labelled, but I'm sure I have some vallisnerias (straight and corkscrew), water wisteria, java fern, hygrophilia, baby tears, water clover, and an aponogeton. There are also two stem plant with big green leaves that I couldn't identify.

The tank is inhabited by two honey gouramis, two pearl gouramis, a male betta, six cories, two German rams, a baby gold nugget pleco, seven neon tetras, and six white cloud minnows.

I do 20% water changes twice a week and use a liquid fertilizer I bought from BigAl's online each time.

I started to have algae problems about a week ago. They grow on the substrate (2-3" Schultz' aquatic soil, topped with 1" of pool filter sand) and on the leaves of the plants. Those on the substrate are light green and form a film that I remove with the gravel vac. Unfortunately, those that grow on the plants - some of them a bright green, some bluish, some reddish - I can't remove without rubbing the leaves - very annoying!

Any ideas how to deal with this problem?

Also: the hygrophilia isn't doing well. The leaves get kinda squishy, then fall off. It grows new leaves quickly, but the whole plant looks sickly.

Thanks for your input!!!

[Wasserpest]

With patience and balance.

Patience... most new tanks go through some algae infestations, and most often they disappear as they appeared... to never come back again.

Balance... takes a while to reach it. "Liquid fertilizer from Big Als"... not sure what it is, but if you overdose in order to get them plants growing... it might contribute to algaes as well. Battling algae with fertilizer is difficult. In a new tank, I would look at the initial growth without adding any fertilizer, especially in what you consider a low light tank. Once you start to see yellowing and stunted growth and holes developing it is time to start feeding.

Besides that, water testing is good, especially to see where your N and P levels are, and to aid keeping those plants green a couple of Otocinclus might give you a hand, I mean mouth.

[Rex Grigg]

It sounds like what you have is BGA. Blue Green Algae which is really not an algae at all. You need to know what your nitrate and phosphate levels are. BGA can be treated with antibiotics, but you still need to find out what is causing it.

Do you have any type of CO2 injection?

[BonesCJ]

In my 25 gallon low light tank i only add Trace+iron to my tank, nothing else. I do have fairly hard water so that might help. How is your water out of the tap for nitrates, nitrites, GH and KH, that could be telling if there is to much or two little. Also i have a hefty snail population consisting of nerite snails (3) and Malyasian trumpet snails (30+) that all eat algea and help keep things clean.

[pufferfreak]

my new 10 gallon is starting to get algea. I don't have any fish in there and ain't useing ferts. Got a diy co2 and 2 watt/per gallon. Need some ottos. IMO

[aquaverde]

NOo fish, no ferts, no food, no mulm- except what your starving plants are going to create! What are your plants supposed to be eating? Part of the drill with CO2 is a fertilization routine. Without it, expect algae, even if your lighting is low- because that is all that will be able to use it.

James

[conny1908]

Thanks for the input, especially about patience and balance!

I have no CO2 injection.

The fertilizer is a "multi-purpose plant food supplement". It contains no phosphates, but has soluble potash, traces of copper, iron (FE), chelated iron, manganese, molybdenum, zinc, and kelp extract - if that is any help.

I'm not sure what N and P are. Nitrogen and phosphates?

Nitrates are 20 ppm. Ammonia and nitrite 0.

Our tap water is very soft, so I added some crushed coral to the substrate, which brought the total hardness up to "moderate", but the buffering capacity is still low (according to the five-in-one test strips I use). pH is 7 out of the tap. According to the test description, the reading I get with the strips won't be accurate unless he buffering capacity is at least at "medium", so I'm not sure what pH in the tank is. Need to get another test kit, I suppose.

[Wasserpest]

Originally Posted by conny1908

Thanks for the input, especially about patience and balance!

:mrgreen: Balance is really the key, since you can get algae problems both with too much and too little... light and nutrients.

Originally Posted by conny1908

I have no CO2 injection.

With soft water, a neutral pH, and low light adding CO2 is not as necessary as with hard water and high light.

Originally Posted by conny1908

The fertilizer is a "multi-purpose plant food supplement". It contains no phosphates, but has soluble potash, traces of copper, iron (FE), chelated iron, manganese, molybdenum, zinc, and kelp extract - if that is any help.

Sounds like a trace mix with potassium. With low light and no CO2 injection (and how densely planted?) you want to be really careful with adding fertilizer to your tank. Stay on the lower limit, or reduce whatever you are adding for a week or two and monitor the results.

Originally Posted by conny1908

I'm not sure what N and P are. Nitrogen and phosphates? Nitrates are 20 ppm. Ammonia and nitrite 0.

That's right, N and P are just used to refer to Nitrates (NO3) and Phosphates (PO4). Tests have shown that a proportion of N to P of 10:1 is the most desirable to keep algae in check. In your case, 20 ppm of NO3 would call for 2 ppm of P. In some areas P is added to the tap water, which can make battling algae a difficult task.

Originally Posted by conny1908

Our tap water is very soft, so I added some crushed coral to the substrate, which brought the total hardness up to "moderate", but the buffering capacity is still low (according to the five-in-one test strips I use). pH is 7 out of the tap. According to the test description, the reading I get with the strips won't be accurate unless he buffering capacity is at least at "medium", so I'm not sure what pH in the tank is. Need to get another test kit, I suppose.

Strips are not the most accurate thing in testing. I would suggest to get liquid dedicated tests for at least pH and NO3, and perhaps PO4 and kH. "Low" and "moderate" isn't precise enough...

[conny1908]

Thanks so much, Wasserpest! I'll ask my LFS for a phosphate test today!

BTW: Your tanks look absolutely phantastic!
And how come you picked the German word for duckweed as your screen name?

[Wasserpest]

Nah, it is Anacharis, not duckweed... that would be "Entengruetze". Also a good user name :lol:
Not sure why the name... because it has some double meaning? Or maybe because that's where I am from? Who knows...

[conny1908]

Originally Posted by Wasserpest

Nah, it is Anacharis, not duckweed... that would be "Entengruetze". Also a good user name :lol:
Not sure why the name... because it has some double meaning? Or maybe because that's where I am from? Who knows...

Hehehe Welcome fellow German!!
And thanks for enlarging my vocabulary!

[malkore]

someone who I recently met, who's kept planted tanks for awhile, suggested this for algae outbreaks: put your lights on a siesta timer. in other words, run the lights for 5 hours, then have them go off for 2 hours, then come back on 5 hours. The plants won't mind this light interuption, but the algae can't cope.

[Kinketsu]

Originally Posted by malkore

someone who I recently met, who's kept planted tanks for awhile, suggested this for algae outbreaks: put your lights on a siesta timer. in other words, run the lights for 5 hours, then have them go off for 2 hours, then come back on 5 hours. The plants won't mind this light interuption, but the algae can't cope.

Would this work as a long-term way to keep a tank? I personally would like to run a morning photoperiod, an afternoon siesta, and then a late-afternoon through late-evening photoperiod, so that I can enjoy my tanks lighted while I'm at home.

If that is OK for the plants, I'd be very happy ... and if it helps against algae, so much the better!

Kinketsu

[Wasserpest]

I heard arguments both for and against it. My guttfeel is that it hurts plants more than algae. I think it is wishful thinking to battle algae this way, and if success is achieved, I would think other factors played a role as well.
Recognizing that algae are the result of an imbalance in your tank is the first step, finding out what that imbalance is would be second, and doing something about it is the logical conclusion.