Help Green dust algae (GDA)

[Joel Armstrong]

What is the cause of green dust algae?

In my tank, I get a small amount of green dust algae on the glass each week. It's not a massive amount, and mostly on the front panel of glass toward the bottom, and a little on the side panels of glass, also toward the bottom. Tank has been planted for a little over 4 months. So relatively new still.

Currently I'm using tap water. At water change I dose new water to N24, P8, K32.

I have a friend who also gets green dust algae on the glass of his tanks. I had a brief conversation with him about it, and he said he has just learned to live with it, and included wiping it off each week as part of his maintenance. Well, with my intriguing nature, I was not really satisfied with his response, and thought I'd create a topic of discussion here.

I've read a bit about it, and I seem to get conflicting information. Some sources say green dust algae is caused from high nitrates coupled with high light, some say it’s strictly from high lighting and not nutrient related at all, or not enough dominant plant mass..

Is it light related?
New tank instability?
Fert related?
Related to the lack of dominant plant mass?
Caused from something in my tap water perhaps?

Mixture of above?


I'm curious to hear from people's experiences with green dust algae accumulating on the glass.

Merry Christmas

#GDA#GDA

 

[Art]

Hey Joel -

Thanks for posting this. I've changed the thread type to "question" so that we can get a "best" solution post. Dealing with algae is something that has evolved over time and there is a LOT of old or misinformation out there. The "best" solution mechanism with question posts allows the current best solution to be highlighted. I also appreciate you using a hashtag to help your fellow members find this later. You're the best, man!

I am going to give you my experience and solution to green dust algae (GDA) and differentiate it from green spot algae (GSA) that is different. GSA is identifiable because it does seem to grow in harder, spots on the glass.

In my experience, GDA is common in biologically immature tanks (new tanks) that are using strong light and fertilization. It comes on relatively quickly and can be scraped off easily during the water change. It's a nuisance but it can and will go away over time as the tank matures.

Here are some things I would recommend:

• Be patient and scrap weekly with water change. There's nothing like setting it back by disrupting it. I scrap with one hand and have the water removal hose in the other trying to suction it out.
• Make sure your CO2 is dialed in for the tank.
• Focus on getting your plants healthy and growing optimally. This includes minimizing detritus build up. The more plants, the better.
• Go leaner on your ferts especially NO3 until your tank settles in. I normally lower by NO3 to 5 ppm and adjust PO4 accordingly.
• Lower your lighting a bit but not to the point that you are negatively affecting the plants.

As you can see, my recommendations are pretty much standard for maintaining a healthy tank but that's what you need for this.

If it is getting out of hand and you want to take more drastic measures:

• I've done a 3 day black-out. Tank glass was crystal clear afterwards. However, unless the instability has been addressed, this is only temporary.
• Some say a UV filter will deal with this in a week or so as its spores are free-floating. I've tried this and felt that it did slow it down but YMMV.
• Some use H2O2 or Excel to dose the tank for a period of time. This also seems to help slow it down, if not eliminate it.

I would stay away from any chemical treatments.

It is curious that you are seeing it lower in the glass. Mine is typically where light is hitting the glass.

Hope that helps. Merry Christmas!

#GDA

 

[GreggZ]

Is it light related?
New tank instability?
Fert related?
Related to the lack of dominant plant mass?
Caused from something in my tap water perhaps?

Mixture of above?

LOL I choose a mixture of above!

I've never really seen anyone nail this one down. I will say in general you do see it more in "hot" tanks with high light and rich nutrients.

But that doesn't mean you have to have it in a hot tank. If I see it creep up I know that something is off and I am usually seeing some on the plants as well at the same time.

First thing I always look at is CO2. Just want to be sure plants have all they need to be in peak health. Next is checking TDS. Is it higher than usual? If so usually means tank is not as uber clean as it could be and too many dissolved organics in the system. Could be as simple as cleaning filters and performing a couple of large water changes to bring things back into balance.

If that's not it then the next thing I always suspect is substrate health. In my opinion it's often overlooked but can be a contributing factor to a lot of problems. One thing people do is vacuum too deep and stir up too much gunk on a regular basis. This can bring on small ammonia blooms which can cause GDA really quickly. For regular maintenance it's better to only disturb the first half inch or so and go lightly. Every once in a while you want to do a deep clean, but not on a regular weekly basis. If you suspect this is a problem for you skip vacuuming for a few weeks and see if you notice a difference.

I know some relate it to fert dosing but I have never noticed a correlation in my tank. With a tank full of fast growing stems too little nutrients can cause more problems than too much. If plants are really healthy and growing fast GDA is usually not an issue.

And many say it's a result of high light. IMO of course high light can exacerbate a situation, but that doesn't mean it's the cause. What I mean is there are very high light tanks that have very little or no GDA on the glass. But get out of balance a bit and higher light will bring it on faster and stronger. So turning down the lights can help, but it's not really a solution. Once you get things back in balance you should be able to turn the light back up with no issues.

So in general my solution is the same solution for most things. Concentrate on keeping uber clean conditions and supply plants everything they need to grow to peak health (light, CO2, nutrients). If those are good then next suspect for me is the substrate.

But those are just my observations. I am curious to hear what thoughts others have.

 

[BigWave]

@Joel Armstrong GDA is an interesting beast. I tried literally everything to rid the stuff beause of constantly being plagued by it. Letting it be to go about its life cycle is the biggest bunch of crap out there. Your plants get covered in it thus plant health declines and then death. A 100% blackout for 3-5 days works but it'll come back, because the problem isnt fixed. As others have said decreasing nutes and lighting helps but it still hangs around. Do not ask me why becasue I dont know but dosing NO3 from KNO3 usually in higher concentrations triggers it. To erradicate it within a few days switch to a different N source such as Urea or even Ammonium Nitrate. Im not saying get rid of the KNO3 all together but lower that dose and add the other N source to make up for the difference. Its worked every singe time for me. Edit to obtain the latter which is banned in quite a few places look for the cheapest instant cold packs you can get. Make sure you read the ingredients before purchasing.... What's Inside an Ice Pack?.

 

[Art]

Edit to obtain the latter which is banned in quite a few places look for the cheapest instant cold packs you can get. Make sure you read the ingredients before purchasing.... What's Inside an Ice Pack?.

Love this!

 

[Joel Armstrong]

Hey Joel -

Thanks for posting this. I've changed the thread type to "question" so that we can get a "best" solution post. Dealing with algae is something that has evolved over time and there is a LOT of old or misinformation out there. The "best" solution mechanism with question posts allows the current best solution to be highlighted. I also appreciate you using a hashtag to help your fellow members find this later. You're the best, man!

I am going to give you my experience and solution to green dust algae (GDA) and differentiate it from green spot algae (GSA) that is different. GSA is identifiable because it does seem to grow in harder, spots on the glass.

In my experience, GDA is common in biologically immature tanks (new tanks) that are using strong light and fertilization. It comes on relatively quickly and can be scraped off easily during the water change. It's a nuisance but it can and will go away over time as the tank matures.

Here are some things I would recommend:

• Be patient and scrap weekly with water change. There's nothing like setting it back by disrupting it. I scrap with one hand and have the water removal hose in the other trying to suction it out.
• Make sure your CO2 is dialed in for the tank.
• Focus on getting your plants healthy and growing optimally. This includes minimizing detritus build up. The more plants, the better.
• Go leaner on your ferts especially NO3 until your tank settles in. I normally lower by NO3 to 5 ppm and adjust PO4 accordingly.
• Lower your lighting a bit but not to the point that you are negatively affecting the plants.

As you can see, my recommendations are pretty much standard for maintaining a healthy tank but that's what you need for this.

If it is getting out of hand and you want to take more drastic measures:

• I've done a 3 day black-out. Tank glass was crystal clear afterwards. However, unless the instability has been addressed, this is only temporary.
• Some say a UV filter will deal with this in a week or so as its spores are free-floating. I've tried this and felt that it did slow it down but YMMV.
• Some use H2O2 or Excel to dose the tank for a period of time. This also seems to help slow it down, if not eliminate it.

I would stay away from any chemical treatments.

It is curious that you are seeing it lower in the glass. Mine is typically where light is hitting the glass.

Hope that helps. Merry Christmas!

#GDA

Hi Art,

Thank you for your response.

Makes sense to change the thread type to "question", all good.

I appreciate you sharing possible methods to minimise or eliminate GDA. Thanks for that.

I am only getting a small amount of green dust algae, and it does appear where the light is hitting the glass for sure, it just seems to be a little more prevalent toward the lower half of the tank.

I'll take note of any changes that I make and observe.

Hope you've had a pleasant Christmas with family and friends.

Cheers..

 

[Joel Armstrong]

GDA algae is a tough one. It's more common in "hot" tanks with lots of light and nutrients.

LOL I choose a mixture of above!

I've never really seen anyone nail this one down. I will say in general you do see it more in "hot" tanks with high light and rich nutrients.

But that doesn't mean you have to have it in a hot tank. If I see it creep up I know that something is off and I am usually seeing some on the plants as well at the same time.

First thing I always look at is CO2. Just want to be sure plants have all they need to be in peak health. Next is checking TDS. Is it higher than usual? If so usually means tank is not as uber clean as it could be and too many dissolved organics in the system. Could be as simple as cleaning filters and performing a couple of large water changes to bring things back into balance.

If that's not it then the next thing I always suspect is substrate health. In my opinion it's often overlooked but can be a contributing factor to a lot of problems. One thing people do is vacuum too deep and stir up too much gunk on a regular basis. This can bring on small ammonia blooms which can cause GDA really quickly. For regular maintenance it's better to only disturb the first half inch or so and go lightly. Every once in a while you want to do a deep clean, but not on a regular weekly basis. If you suspect this is a problem for you skip vacuuming for a few weeks and see if you notice a difference.

I know some relate it to fert dosing but I have never noticed a correlation in my tank. With a tank full of fast growing stems too little nutrients can cause more problems than too much. If plants are really healthy and growing fast GDA is usually not an issue.

And many say it's a result of high light. IMO of course high light can exacerbate a situation, but that doesn't mean it's the cause. What I mean is there are very high light tanks that have very little or no GDA on the glass. But get out of balance a bit and higher light will bring it on faster and stronger. So turning down the lights can help, but it's not really a solution. Once you get things back in balance you should be able to turn the light back up with no issues.

So in general my solution is the same solution for most things. Concentrate on keeping uber clean conditions and supply plants everything they need to grow to peak health (light, CO2, nutrients). If those are good then next suspect for me is the substrate.

But those are just my observations. I am curious to hear what thoughts others have.

Thanks Gregg,

Also very helpful information here.

What seems to stand out for me are your comments about the substrate. Several weeks ago, I came to the conclusion my maintenance was not up to scratch, particularly in regard to effective vacuuming.
I did perform a deeper vacuuming of the whole tank, followed by several large water changes. I didn't go all the way to the bottom, but I did disturb the top 2 inches or so. Each week since, I have been vacuuming but perhaps going a little too deep still. So, yes I suspect this has been a problem for me.

I think I'll keep dosing the same, keep the lighting the same and just vacuum much lighter than what I have been, or perhaps even skip vacuuming for a couple of weeks like you suggested.

Hope you've had a pleasant Christmas with family and friends also.

Thanks again.

 

[Joel Armstrong]

@Joel Armstrong GDA is an interesting beast. I tried literally everything to rid the stuff beause of constantly being plagued by it. Letting it be to go about its life cycle is the biggest bunch of crap out there. Your plants get covered in it thus plant health declines and then death. A 100% blackout for 3-5 days works but it'll come back, because the problem isnt fixed. As others have said decreasing nutes and lighting helps but it still hangs around. Do not ask me why becasue I dont know but dosing NO3 from KNO3 usually in higher concentrations triggers it. To erradicate it within a few days switch to a different N source such as Urea or even Ammonium Nitrate. Im not saying get rid of the KNO3 all together but lower that dose and add the other N source to make up for the difference. Its worked every singe time for me. Edit to obtain the latter which is banned in quite a few places look for the cheapest instant cold packs you can get. Make sure you read the ingredients before purchasing.... What's Inside an Ice Pack?.

Hi Steve,

Thanks for chiming in here, definitely some helpful comments to think about.

I've read in various places to let it go, but I haven't wanted to let it go about its life cycle either.

As I'm only really getting small amounts of GDA, and the fact that I'm reasonably new to DIY ferts, I'm hesitant in switching to other sources of N just yet. I'll keep this in mind though.

Thank you Steve, hope you had a great Christmas

Cheers

 

[Art]

Joel,

IME, as the tank matures and you keep things consistent, the GDA will reduce. I normally get to the point where I don’t need to scrape the glass weekly. However, when I ultimately scrape the glass on week 2 or 3, I realize that there certainly was a thin coating of GDA on it. It’s just very light and slow growing.

My point is that most tanks will have GDA but it should be extremely manageable.

 

[OmidNiav]

I've been dealing w GDA in my Dutch for a while now. Need to do more frequent maintenance. I think like all other algae it is a multifactorial issue but in my opinion NO3 and high light contribute. Leaving it alone to die never worked for me.

 

[mn_aquascape]

Honestly GDA is one of the reasons I switched to the APT line of minerals and ferts. I get it, I'm paying a premium for pre-made stuff. Dennis isn't shy about his claims that many aquarists feel that wiping GDA off glass is a normal part of maintenance - but it shouldn't be. So I figured I'd put him to the test.

I've decided to give his entire line a try for a while. If nothing else, someone much smarter than me has spent a lot more time thinking about what nutrient and mineral ratios should be. Maybe I can capitalize on that. It's kinda hard to argue with his results (though I'm guessing we don't always see everything). There are some nice scapes out there from people using his stuff.

Anyways, I'm about 2 weeks in now, and I feel like I'm seeing a notable difference in the scape. Pearling is more intense than I've ever seen, and GDA is the least noticeable I've ever seen. Usually im wiping glass about 3 days post maintenace day... but I'm easily getting to day 5. And I would say I'm not completely on the new program yet since it's only been about 2 weeks, and 2 x 50% waterchanges. I haven't changed anything else with my routine, or lights or filtration or anything else I can think of. Just started using APT sky minerals and ferts.

I'm not very helpful, because I don't measure anything anymore. I just follow the directions on his packaging. So I can't tell you what's changed as far as my NPK or GH (Ca:Mg).

--Steve

p.s. - not sponsored.

 

[Art]

Steve, you're making a great point here. With commercial products, there is a certain level of trust we must put in the manufacturer. Sure, they can lie to us and there is no doubt many do. However, the consumer has a responsibility to do their homework on who they spend money with.

Dennis has shown himself to be extremely knowledgeable in this area and he shows his results. He doesn't claim to be perfect or that algae will never get you if you use his products. However, he does tell you that he takes his knowledge and applies it to his products. That is all I ask from a manufacturer/retailer. He is also responsive and is a fellow hobbyist. All of this inspires trust.

If it makes economic sense and you don't have the desire to roll your own, then a product like Dennis' is the right thing for you.