Question How To Find The Cause Of Algae

[jake37]

I have a 120g tank that has been setup for 3 1/2 months. Very recently (last week or so) algae has begun to grow on stem plants (it is hairy green stuff) so something is a bit out of balance but i'm not sure how to figure out what.
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I do water changes once or twice a week - 25% or 30 gallons. I have two fluval 3.0 lights (one 36 and one 48) the lights start at 8am and reach full intensity at 9am; conversely they start to dim at 4pm and go off at 5pm (or 7 to 9 hours depending how you count).
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I put in a small amount of flourish excel and thrive+ once a week - usually 3 cap full of excel and 6 pumps of thrive+. I also use some random number of root tabs once every 4 to 6 weeks (around 6).
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Is there an easy way to quickly identify the cause of the algae (what is out of balance).

 

[Salem]

I would first test to see how many nitrates you have, anything above 10 will promote algae growth. I doubt it would be your lights if youve been using them the whole time. You could also try seeing if it calms down if you use less of the fertilizer

 

[kallililly1973]

Pics would help to see what type of algae is showing up.

 

[Nick72]

I suspect it's a combination of medium to high lighting, combined with low and fluctuating nutrient levels, and low CO2.

I'd suggest your lighting is fine, but would be interested to see how you have arranged the two lights.


The Excel is fine as an algaecide but would work better if used daily in smaller quantity, but it's no substitute for CO2.

I would dose with Thrive+ at least three times a week.

 

[jake37]

I'll take a photograph later when the lights come on - the tank nitrate run between 15 and 20ppm due to heavy water changes. The tank population has not changed in 2 months but it is fairly high at:
4 clowns (2.5 to 4 inches)
5 zebra (striata botia)
10 kuhli
1 upside down
7 otto
2 bn pleco
6 sterbai cory
3 guppies
2 swordtails
21 cardinal tetra
3 head/tail tetra
4 angel fishes
2 visible frys (who knows what else is hiding where)

 

[leftswerve]

I'll take a photograph later when the lights come on - the tank nitrate run between 15 and 20ppm due to heavy water changes.........

50% is heavier.

 

[jake37]

Ok - nitrate run between 15 and 20ppm due to light water change.

50% is heavier.

 

[ryanr]

Hi,
Treating algae can be a difficult task.
The first step is to identify the type algae, then from there, you can identify the likely cause(s).

The following website is a great resource for identifying and treating the causes of many common algae Aquarium Algae ID (updated May6th '10 Surface Skum)

 

[jake37]

Here are two pictures - the first is the entire tank the second shows the algae on one of the stem plants. The algae is mostly just on the stem plants and on the right side of the tank; the stem plants on the left side are algae free. The plants in the pot are for a new tank that was delayed being setup and the green thing in the middle front is a fry net with 2 frys i found in the canister filter:

 

[Chanyi]

Too much light - Reduce to 5 hours per day or turn them down to 50-75% output.
Too little CO2. - Not much you can do about this unless you purchase a pressurized system. Nonetheless, without CO2 you can't run that amount of light off the get go, 3.5 months is still a relatively new tank.
Too little amount water changed. - Go with 50% weekly or greater.
Varying nutrient levels. - Dose Thrive as recommended with a 50% water change.
Improper use of of Excel. - Dose the "after water change" rate daily.

 

[jake37]

Does excel truely replace injected co2 and if not what is the cheapest (safe for fish) non dyi way i can add co2 ? Also if i reduce light which spectrum ? One change i made recently with the fluval software update is added 3 hours of blue light to view the fishes (at 10%) could it be this blue light that is causing the algae ?

 

[DoubleDutch]

I suspect it's a combination of medium to high lighting, combined with low and fluctuating nutrient levels, and low CO2.

I'd suggest your lighting is fine, but would be interested to see how you have arranged the two lights.


The Excel is fine as an algaecide but would work better if used daily in smaller quantity, but it's no substitute for CO2.

I would dose with Thrive+ at least three times a week.

Uhhhh Excel is a substitute for CO2 Nick.
It is a different kind of Carbonsource used by plants.

OP, did you check the phosfates as well?

 

[Nick72]

Does excel truely replace injected co2 and if not what is the cheapest (safe for fish) non dyi way i can add co2 ? Also if i reduce light which spectrum ? One change i made recently with the fluval software update is added 3 hours of blue light to view the fishes (at 10%) could it be this blue light that is causing the algae ?

There is only one reliable way to add CO2 - a pressurised CO2 system.

That's anything from $120 to $300 to install, and about $30 USD a year to keep running.

Excel is an algaecide. It adds no CO2.

Blue light is notorious for growing algae.

I leave my Fluval Plant 3.0 on the manufacture settings for a planted tank. Around 20% blue light. But my light is on for 8 hours, the other 16hrs it's completely off.

IMHO you don't have an algae problem, you do have a nutrient problem. Most of your plants are showing signs of nutrient deficiency. Sort this out and your algae will sort itself out.

 

[Nick72]

Uhhhh Excel is a substitute for CO2 Nick.
It is a different kind of Carbonsource used by plants.

OP, did you check the phosfates as well?

Sorry @DoubleDutch we are going to have to disagree here

The whole Excel CO2 thing is the biggest marketing scam in the hobby.

It's a simple algaecide and a good one. It does nothing to contribute CO2

 

[jake37]

So more feritilizers or more fish and turn off the 3 hours of 10% blue light.

There is only one reliable way to add CO2 - a pressurised CO2 system.

That's anything from $120 to $300 to install, and about $30 USD a year to keep running.

Excel is an algaecide. It adds no CO2.

Blue light is notorious for growing algae.

I leave my Fluval Plant 3.0 on the manufacture settings for a planted tank. Around 20% blue light. But my light is on for 8 hours, the other 16hrs it's completely off.

IMHO you don't have an algae problem, you do have a nutrient problem. Most of your plants are showing signs of nutrient deficiency. Sort this out and your algae will sort itself out.

 

[Nick72]

So more feritilizers or more fish and turn off the 3 hours of 10% blue light.

That would be a good starting point.

 

[Chanyi]

Yep, I agree, Excel is not a carbon source. It is an algaecide + it helps break down protein films growing on plant leaves allowing them better access to atmospheric CO2 levels dissolved in equilibrium in the water.

Next myth, excess nutrients cause algae. No. Sky high NO3 or the presence of PO4 does not = algae. Imbalances of these nutrients / inconsistencies + too much light and too little CO2 is the recipe for algae. Excess organics is another huge factor. Eliminate them, clean the heck out of the filter and substrate during each / every other water change. A clean tank + filter + substrate / strict maintenance schedule is a very good habit to get into for keeping on top of algae.

Organics dissolve into plant nutrients yes, but it also feeds algae, especially ammonia. If we remove all the organics before we allow them to dissolve, we can easily dose fertilizers for pennies to feed the plants, not the algae.

Ill plants / sick plants / stunted or poor growing plants are algae magnets. The decaying plant tissue is a buffet for algae spores. Remove them by trimming dying tissue or removing these plants. (meaning filter cleaning because dead / broken off plant tissue gets sucked into the filter).

 

[DoubleDutch]

Sorry @DoubleDutch we are going to have to disagree here

The whole Excel CO2 thing is the biggest marketing scam in the hobby.

It's a simple algaecide and a good one. It does nothing to contribute CO2

Ahhhh okay. Not gonna jump in that discussion cause I don't know enough about it. I was always told it was a carbon-substitute, a side-effect of an insecticide sprayed into seacontainers to kill bugs.

Never used it and never will.

 

[jake37]

Would simply adding more root tabs solve the problem ? Rather not add co2 - not so much cost but concern of goofs.
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I don't have any way to test for phostate. I have api kit (nitrate, nitrite, amonia, ph) and a hardness kit. I also have a tds meter that sez reads around 130 (+/- 10).

 

[Dechi]

What intensity do you use on your Fluval ? Without CO2, you shouldn’t go more than 50%-65% for the whites at the brighest part of the day, and no more than 4-5% blue light. And maybe 15% red light.

I just started getting a little bit of green algae after 3 months. My settings were at 50% for a long time, then a month ago I set it to 65%. Yesterday I brought it down to 52% and reduced lighting hours a tiny bit.