Heavily Planted Tank + No ferts + 0 Nitrates = Green Water?

Over the past few months I have been having to keep battling with green water with a UV sterilizer, I would always just chalk it up to high levels of nitrates from my plants, food, and fish waste.

I've gotten a green water bloom again so I decided today I'd do an API Test kit of all three ammonia, nitrites, nitrates. To my surprise they all came back to 0, which has me wondering why I keep getting the green water algae bloom? Or perhaps my plants are just eating up all the nitrates very quickly and so my reading comes back at 0?

Any ideas?

Its heavily planted 40 breeder, I feed very generous amounts, and the tank has CO2 + high lights

 

You're limited by the lack of nutrients in the water column.

I would assume the plants are sucking up any waste then waiting for their next source. Since the tank is not balanced algae grows is my best guess.

Maybe try dosing thrive.

 

You're limited by the lack of nutrients in the water column.

I would assume the plants are sucking up any waste then waiting for their next source. Since the tank is not balanced algae grows is my best guess.

Maybe try dosing thrive.

I think you might be right, will try to rid the green water with the UV and start dosing to see how well it works

 

I would definitely think that with to ur plant mass (which looks great) you might be capping it out. Maybe try upping the dose by 25% and see how that affects your levels. Although the tank doesn’t look very green in the picture?

 

Yes I think with that amount of plants you need to be dosing ferts, one that includes nitrate. Without it the plants struggle to compete with the algae.

 

Tank looks great. Can't see the green water as well as you obviously. Maybe try manually stirring the carpet around to see if any extra detritus is stuck down deep and do that a few times right before your WC to see if that helps clear it up. That was happening to our heavily planted 29 we had outside last year but stirring it around and doing big WC's 75% or so and i think it will help out.

 

I think all of the advice given here is spot on and is basically leading to the same point, the lack of nutrients for the plants by not dosing ferts is probably causing them to not be able to compete with the algae causing the blooms.

As far as the green water look, I cheated and posted a photo of the tank when it didn't have green water, here it is with:

 

I think all of the advice given here is spot on and is basically leading to the same point, the lack of nutrients for the plants by not dosing ferts is probably causing them to not be able to compete with the algae causing the blooms.

As far as the green water look, I cheated and posted a photo of the tank when it didn't have green water, here it is with:

View attachment 731342

Wait... I'm confused with all of this. If there are zero nutrients in the water algae will not grow. How does algae grow without nutrients?

I would disagree with everyone above. If you add more nutrients, I would only anticipate the algae getting worse not better. In addition, everyone seems to be equating zero nitrates with zero nutrients in the water. This is not correct.

I would attribute the greenish water (will have to take your word for it, hard to tell from the picture) in this case as too much light and/or too many nutrients in the water. You haven't disclosed your water change habits, but this can both help and aid the algae depending on your source water. ie you can help it by removing excess nutrients or even sometimes hurt it by adding more nutrients to the aquarium based on your source water. I also would want to know the lighting period. Although CO2 can help cover for this, I suspect it is on for too long.

 

Wait... I'm confused with all of this. If there are zero nutrients in the water algae will not grow. How does algae grow without nutrients?

I would disagree with everyone above. If you add more nutrients, I would only anticipate the algae getting worse not better. In addition, everyone seems to be equating zero nitrates with zero nutrients in the water. This is not correct.

I would attribute the greenish water (will have to take your word for it, hard to tell from the picture) in this case as too much light and/or too many nutrients in the water. You haven't disclosed your water change habits, but this can both help and aid the algae depending on your source water. ie you can help it by removing excess nutrients or even sometimes hurt it by adding more nutrients to the aquarium based on your source water. I also would want to know the lighting period. Although CO2 can help cover for this, I suspect it is on for too long.

The pants can be hindered by the weakest link. Algae needs much less to thrive than what plants do. The fact that the tank has zero nitrates so his plants are zeroing them out. Based on the post it says they’re not currently dosing but feeding heavily and using Co2.

chances are due to a deficieny in one aspect it is causing others to become abundant and allowing the green water algae to thrive.

 

Here's another far-fetched idea... parroting this from a problem I had in a saltwater tank with green hair algae, which is sort of the SW equivalent to black beard algae, not the hair algae we are used to...but I digress.
It was suggested to me at the time that the algae was binding the nitrates (and phosphate, in my case) so quickly that I never got a reading for them. That algae was using the nitrate up as fast as it was being produced. But I guess that would go back to the previous idea of dosing fertilizers with nitrate in order to let your plants compete with the algae.

 

Here's another far-fetched idea... parroting this from a problem I had in a saltwater tank with green hair algae, which is sort of the SW equivalent to black beard algae, not the hair algae we are used to...but I digress.
It was suggested to me at the time that the algae was binding the nitrates (and phosphate, in my case) so quickly that I never got a reading for them. That algae was using the nitrate up as fast as it was being produced. But I guess that would go back to the previous idea of dosing fertilizers with nitrate in order to let your plants compete with the algae.

This is a relevant point since sometimes the instinct to cut nutrients but it’s counterproductive as it takes away the plants ability to thrive and gives the algae more of a stronghold.

 

The pants can be hindered by the weakest link. Algae needs much less to thrive than what plants do. The fact that the tank has zero nitrates so his plants are zeroing them out. Based on the post it says they’re not currently dosing but feeding heavily and using Co2.

chances are due to a deficieny in one aspect it is causing others to become abundant and allowing the green water algae to thrive.

That's fine, but plants use the same nutrients as the algae... The fact that there is algae growth means that the premise that there is not enough nutrients (or zero nutrients) is a fallacy.

So the algae is outcompeting the plants (1) or you have way too many nutrients in the water/too much light (2). If plant growth has stalled, then that is your cause (#1). If the plants are still excelling, then the cause is (#2).

Based on the stationary pictures, it looks as though the plants are doing fine so that is why my inclination would be cause #2. But that is just going off two pictures.

 

Over the past few months I have been having to keep battling with green water with a UV sterilizer, I would always just chalk it up to high levels of nitrates from my plants, food, and fish waste.

I've gotten a green water bloom again so I decided today I'd do an API Test kit of all three ammonia, nitrites, nitrates. To my surprise they all came back to 0, which has me wondering why I keep getting the green water algae bloom? Or perhaps my plants are just eating up all the nitrates very quickly and so my reading comes back at 0?

Any ideas?

Its heavily planted 40 breeder, I feed very generous amounts, and the tank has CO2 + high lights


View attachment 731181

i love your tank it is so beautiful

 

This is not entirely about nutrients in my opinion. My guess would be that your photo period is too long. High lighting allows your plants to use the available nutrients and CO2 most effectively, but if the nutrients are only available in small quantities your plants simply cannot make use of it all. So your algae is basically having a field day with all the light and CO2 it can ever want. My advice would be to lower your photo period to 7 hours for awhile and start dosing Thrive. Make sure your CO2 is off at night. I would recommend running an airstone at night as well but it isn't necessary. Once your tank is balanced again you can bump your photoperiod up to 8 hours with a 2 hour siesta halfway through the day. So 4-2-4. Keep running your UV sterilizer and keep an eye on things

 

Some very interesting points here. I will keep this thread updated once I get the UV sterilizer on and start dosing. And see if the green water comes back.

The photo period for the tank is currently from 4:30PM to 11:30PM

I have an air driven filter that turns off at 3 and my CO2 kicks on at 3:30, and then at 10:30 my CO2 shuts off and my air pump turns on at 11.

I think a test that I should do is check my water parameters once the green algae is gone to set a baseline of where my nitrates land when there is no algae. Then we can surely say the plants are eating the nutrients effectively and the lack of them could cause them to not compete correctly

 

Nuisance algae is always caused by an imbalance between light, nutrients & co2. If you have high light and co2 injection it is essential to be dosing complete ferts at the required level.

 

That's fine, but plants use the same nutrients as the algae... The fact that there is algae growth means that the premise that there is not enough nutrients (or zero nutrients) is a fallacy.

So the algae is outcompeting the plants (1) or you have way too many nutrients in the water/too much light (2). If plant growth has stalled, then that is your cause (#1). If the plants are still excelling, then the cause is (#2).

Based on the stationary pictures, it looks as though the plants are doing fine so that is why my inclination would be cause #2. But that is just going off two pictures.

I would agree here and the first post from this user.

This is most likely not cause by a deficiency but an imbalance, because that is the root cause for all algae.

And as this poster mentioned, water changes play into all this.

So there an imbalance somewhere. Light, co2, micro and macro nutrients all matter and one of them (or more is off). I have found light to be prime suspect for green water. Adding too much light to an nutrient imbalanced tank will cause issues.

Do you have a phosphorus test? I’d recommending narrowing down the imbalance and start with the light.

 

I would agree here and the first post from this user.

This is most likely not cause by a deficiency but an imbalance, because that is the root cause for all algae.

And as this poster mentioned, water changes play into all this.

So there an imbalance somewhere. Light, co2, micro and macro nutrients all matter and one of them (or more is off). I have found light to be prime suspect for green water. Adding too much light to an nutrient imbalanced tank will cause issues.

Do you have a phosphorus test? I’d recommending narrowing down the imbalance and start with the light.

don’t believe I do but will see if I can figure that out

 

Hello All,

Wanted to provide an update here,

It's been about two months now with the green water all cleared out. I believe the assumptions here with the no ferts was correct.

Some of my harder plants did suffer recently due to an issue with my CO2 and no fertz, but the green water has been kept in check so far, water has been crystal clear.


So I believe Light + CO2+ Ferts, the combination of all three of these give you the good growth and algae fighting, which has been known for a while now...I was just reluctant to follow it haha.


The guppy population in the tank has exploded, theres roughly 30+ fry in the tank with about 9 adults. Although you'd never be able to tell because of how well they hide in the plants.

 

Nice tank, lol good to see another floodlight user. Definitely looks like ferts have helped.

 

Nice tank, lol good to see another floodlight user. Definitely looks like ferts have helped.

The par / $ savings is too hard to pass up haha