# Causes and solutions for green spot and staghorn algae?



## Bars (Nov 11, 2019)

Whenever I try my hands on a planted tank, I have an ongoing battle with, I think, staghorn algae and green spot algae.

Infos:
- Restart the tank about 6 - 8 weeks ago after bad experiences with ADA. Switched to plain pool filter sand with root tabs. All stem plants were bought at the same time.
- Water volume: 100 liter/ ~ 26 gallon
- Filtration: 800 liter/hour from canister + 600 liter/hour powerhead. Circulation doesn't seem to be the problem. All plants are gently moving in the flow and all substrate and decor is clear from detritus. Weekly 50% water changes
- Light: Aquamedic Qube 50 at 100% intensity, on for 9 hours a day. No direct sunlight.
- CO2/dosing: dropchecker's always lime green using pressurized CO2 with an inline diffusor. I'm dosing according to the EI method (KH2PO4, KNO3 mon - wed - fri - sat and trace elements tue - thu - sat - sun, saturday is water change day)

So.... The problems! 
First off, green spot algae. If I don't clean the glass it turns almost completely green with green spot algae after about a week. I noticed my Alternanthera leaves are covered with them as well (mostly older/lower leaves). Did some research and found something about a lack of macros, so I started doubling those doses just last week. Am I wrong in thinking that's the cause? Ever since I increased the doses, my second problem has increased significantly. 

Second problem! Pretty sure it's staghorn, because I've been dealing with that stuff for so long. It started about 2 or 3 weeks ago on the hardscape, but has now spreaded to my Echinodorus ozelot and red rubin. As stated before, the spreading started after increasing the macro doses.

I'm kind of at a loss. Every source I find states that staghorn takes over when 1) CO2 levels are too low (not the case for me), 2) poor water circulation (which I'm sure is plenty as well), 3) dirty substrate (it's 8 weeks old, cleaned thoroughly and is still very clean whenever I disturb it) or 4) high ammonia levels. If I'm correct, I'd be having cloudy and smelly water as well if ammonia levels were too high, right? My water's crystal clear and doesn't smell, neither are my fish dying or doing poorly in any way.

And a third problem, which might not be related to the algae issues, but I thought it'd be worth mentioning. The new stem plants aren't doing too great either. The Rotalas are showing some submersed growth, but are growing extremely slow and look a bit deformed. Alternanthera did great the first few weeks, but after trimming seems to be losing some color, isn't growing that well anymore and is starting to get taken over by green spot algae. The water sprite (not sure if that's a stem plant), which is planted in the substrate as well, is growing like crazy though.

Any thoughts? I feel like it might be a combination of too much dosing, too long of a photoperiod and, I'll admit it, a bit of overfeeding. The lack of growth in the stem plants makes me feel like I'm not dosing _enough_ though, considering CO2 levels are fine.


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## Rotala macrandra (Mar 2, 2020)

Plants have noticeable nutrient disorders which results in weakened leaves and allows for algae to grow. Dosing more will not alleviate the problem, only exacerbate it. 



> Did some research and found something about a lack of macros, so I started doubling those doses just last week. Am I wrong in thinking that's the cause?


Completely wrong.



> Every source I find states that staghorn takes over when 1) CO2 levels are too low (not the case for me), 2) poor water circulation (which I'm sure is plenty as well), 3) dirty substrate (it's 8 weeks old, cleaned thoroughly and is still very clean whenever I disturb it) or 4) high ammonia levels


Correlation /= causation. Virtually every online source is wrong about the causes of algae. Do not believe anything you read on the internet.



> The Rotalas are showing some submersed growth, but are growing extremely slow and look a bit deformed. Alternanthera did great the first few weeks, but after trimming seems to be losing some color, isn't growing that well anymore and is starting to get taken over by green spot algae. The water sprite (not sure if that's a stem plant), which is planted in the substrate as well, is growing like crazy though.


Excessive Fe is my guess which is inducing deficiencies.

Exactly what are you dosing and in what concentrations?


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## somewhatshocked (Aug 8, 2011)

Please ignore this guy. He's permanently banned for stirring the pot like this and insulting other members.



Rotala macrandra said:


> Plants have noticeable nutrient disorders which results in weakened leaves and allows for algae to grow. Dosing more will not alleviate the problem, only exacerbate it.
> 
> 
> 
> ...


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## burr740 (Feb 19, 2014)

The swords would probably benefit from a couple root tabs. You can find aquarium brands such as Seachem or use Osmocote Plus (push 10-12 single balls around each each sword, and one or two under the AR for good measure) If you go the Osmocote route be sure to get the "Plus", the regular only has macros, the plus has everything

Where are you getting your EI dosing from? Reason I ask is because a couple years ago Fe/micros was lowered to .2 ppm 3x per week, down from the original .5 3x per week.

Some places, well most really, still show the amounts for .5 ppm 3x. Which yes, is a little rich and can certainly cause issues for some people. Thats why it was changed in the first place and Tom was in on the decision, albeit somewhat begrudgingly  The calculator at rotalabutterfly.com is adjusted to .2

I wouldnt change macros from EI except maybe use a little more PO4. Something like 1.7-2 ppm doses instead of 1.3 ppm doses. Works better for a lot of folks

Tank looks nice overall and very clean. Just get those swords happy and everything should be OK. Those are two big plants. Struggling plants get algae, and the by product of degrading leaves feeds algae in other areas


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## Bars (Nov 11, 2019)

burr740 said:


> The swords would probably benefit from a couple root tabs. You can find aquarium brands such as Seachem or use Osmocote Plus (push 10-12 single balls around each each sword, and one or two under the AR for good measure) If you go the Osmocote route be sure to get the "Plus", the regular only has macros, the plus has everything


I'll add some more tabs! Already had some spread around, but not nearly as much as you recommend. 



burr740 said:


> Where are you getting your EI dosing from? Reason I ask is because a couple years ago Fe/micros was lowered to .2 ppm 3x per week, down from the original .5 3x per week.


I'm getting my stuff from a Dutch website: https://aquariumbemesting.nl/nl/home
As for micros I'm dosing Tenso cocktail. Just had a look at the bags and I noticed I'm dosing waaaaay too much. Recommended is 6 ml/ week, which I'm doing 4 times a week. 

Also, what exactly should I dose for macros? At the moment I'm looking at 3 bags, KH2PO4, K2SO4 and KNO3. I'm 99% I'm only using KH2PO4 or KNO3, not all 3 of them, because I didn't remember having K2SO4. I mix 4 grams of the phosphates in 500 ml water and used to dose about 10 ml 4 times a week. Doubled that to 20 ml since last week. KNO3 calls for 41 grams in 500 ml water and again 10 ml 4 times a week.

I never really paid close attention to how much I dose and it has never been very clear to me exactly what I need. Got so many different answers/views/opinions etc. that I'm really just throwing some stuff in it and making sure nothing in the tank dies. 

Apologies if I missed anything, just wrote this real quick before heading to work.


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## burr740 (Feb 19, 2014)

Bars said:


> I'll add some more tabs! Already had some spread around, but not nearly as much as you recommend.


OK just to be clear, when I said "10-12 single balls" - that only pertains to using Osmocote Plus, which comes loose in tiny balls. 

Actual root tabs, a couple of fresh ones under each sword should do the trick. But not 10 or 12! lol



Bars said:


> I
> I'm getting my stuff from a Dutch website: https://aquariumbemesting.nl/nl/home
> As for micros I'm dosing Tenso cocktail. Just had a look at the bags and I noticed I'm dosing waaaaay too much. Recommended is 6 ml/ week, which I'm doing 4 times a week.
> 
> ...


Tenso is pretty good stuff, better ratios than csmb actually. If you were OD'ing on that its probably your primary issue. 

As for macros you should be fine using just KNO3 and K2SO4, both provide K. Some folks like to add a little bit extra via K2SO4. It wouldnt hurt to have a pound on hand just in case you see a need down the road. Might as well get it shipped in with the other two since shipping probably costs more than the product itself.

KNO3 - 7 ppm 3x per week
KH2PO4 - 1.7 ppm 3x per week

*assumes a good 50-60% weekly water change

If you need help arriving at those numbers, how much to add to the dosing bottle or for dry dosing, etc, give the details and someone can run the numbers for you. For making a solution need to know tank size, dosing container size, and the size of each dose you're using


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## PlantedRich (Jul 21, 2010)

It is a natural thing to have many doubts and missing small details when dealing with nature. You may note that gardens are not always looking their best and gardeners often search for clues, even after a lifetime of doing it? Same goes on our water plants as things that work in one tank where water and plants are different and may need change. Not all plants need the same and not all water has the same, so it does take some adjustments, so consider ALL recommendations as simply starting points and then look for small point that may need to be adjusted. You are very correct to search for answers but do not follow those answers blindly but consider, try and perhaps keep the ones which work. 
If it was simple, everybody would have tried it and it might be totally boring, so look at it as a fun challenge but don't sweat over not getting perfect. I thought I had it around here at one point but I often lose it! 
Look, learn, and adapt as needed!


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## Bars (Nov 11, 2019)

burr740 said:


> OK just to be clear, when I said "10-12 single balls" - that only pertains to using Osmocote Plus, which comes loose in tiny balls.
> 
> Actual root tabs, a couple of fresh ones under each sword should do the trick. But not 10 or 12! lol


I've always made them myself, large marble sized balls, hence the confusion haha.



burr740 said:


> Tenso is pretty good stuff, better ratios than csmb actually. If you were OD'ing on that its probably your primary issue.
> 
> As for macros you should be fine using just KNO3 and K2SO4, both provide K. Some folks like to add a little bit extra via K2SO4. It wouldnt hurt to have a pound on hand just in case you see a need down the road. Might as well get it shipped in with the other two since shipping probably costs more than the product itself.
> 
> ...


Thanks, I'll have a good look at it this weekend


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## Bars (Nov 11, 2019)

Quick update. I've cut down both trace and macro dosing. 

Trace: 2 ml/ 3x a week. Packaging says 6 ml a week is recommended.
KNO3: packaging says 10ml/100 liter wil increase nitrates by 5.0 ppm. Dosing 8 ml 3 times a week.
KH2PO4: packaging says 10 ml/100 liter will increase phosphates by 0.5 ppm, also doing 8 ml 3 times a week.

I trimmed all the Echinodorus leaves that had any algae on it and cut down most of the Alternanthera. I'm going to continue to remove any affected leaves I can see. Some of the algae that's growing on the wood has turned a bit red.

Will any leftover algae eventually die or do I have to remove everything manually? Some of my Bucephalandra leaves have just a few single 'hairs' on them. It'd be a day job to get rid of all the algae.


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