# Green water algae after no water change for 2 weeks (high tech)- how to treat root cause?



## Animallover (8 Nov 2021)

Hi guys,

I was away for 2 weeks and no one I live with were happy to do weekly water changes. During this time EI dosing was continued and no other changes except for 1 missed 50% weekly water change on day 7 after I left. When I returned the water looked less clear than usual (nothing crazy but noticeable) but the main issue was on the top there was a film of algae floating completely on the surface of the water not attached to anything in particular. I done 3 big water changes over the next week and continued everything as normal. The water is completely clear for the first few days post water change but by the time its day 7 it just has that semi green tinge and the layer at the surface of the water. It's not the end of the world as still looks fine but I do prefer crystal clear looking water throughout the 7 days prior to water change as before. 

How can I fix this? I thought the water changes would fix any imbalances of nutrients but its been about 1 month and cleary the algae is not going anywhere. Plants and fish are all happy and healthy. I checked UV but apparently not the best for the EI dosing as can mean less absorption by plants of those nutrients and also checked blackout method but seems quite extreme when it's not overwhelming. Plus these don't address the root cause. 

Just wondering how to fix the root cause instead of just temporarily getting rid of it. 

Any help would be appreciated.

Thanks!


----------



## Animallover (11 Nov 2021)

Just some pictures to show how it looks. You can see where the filter outputs are there is crystal clear water but the rest of the water (at the surface mainly) looks murky green. Any help would be appreciated! 

Thanks!


----------



## Hufsa (11 Nov 2021)

Oof, that doesnt look good. Its a bit of a puzzle this.. has there been any other changes in care of the tank? New kind of fish food, or change in amounts of fish food, or has someone else been feeding (could be feeding more) ? Plants do look very nice from what the pictures show..


----------



## MichaelJ (12 Nov 2021)

Animallover said:


> I checked UV but apparently not the best for the EI dosing as can mean less absorption by plants of those nutrients and also checked blackout method but seems quite extreme when it's not overwhelming. Plus these don't address the root cause.


Hi @Animallover  Well, this certainly fall into the category where UV would help - if its a floating green algae problem its definitely worth considering throwing some UV at it and keep up those WCs until the problem goes away - I've recently fixed a problem with cloudy water with great success  (cloudy for other reasons though). It's puzzling that a short lapse in WC/maintainance would cause this - sounds coincidental to me... unless something was going on with the tank that you are not aware of while you were away - such as overfeeding, CO2 failure, switching off filtration by accident etc... Perhaps someone else can shed more light on this one.

If you deploy a UV filter, just make sure you switch it off for say 6 hours after dosing traces (Iron in particular).


As @Hufsa said, plants and tank otherwise looks great though.

Cheers,
Michael


----------



## Wookii (12 Nov 2021)

Is the layer on the surface not just a typical protein surface scum, or is the first couple of inches of water affected rather than just the white slick on the surface? 

If mainly the former, then a skimmer should get rid of it in fairly short order:

Amazon product


----------



## tiger15 (12 Nov 2021)

I treated green water in my shrimp bowls with live daphnia.  They cleared up the water in few days and became shrimp food when they dropped dead after algal food is exhausted.  It works for me because I have a daphnia source from my outdoor tub culture and I have no fish to prey on live daphnia.  But I heard that you can protect  the daphnia in a brine shrimp net in a fish tank to do the job, provided that you can find live daphnia.


----------



## Animallover (12 Nov 2021)

Hufsa said:


> Oof, that doesnt look good. Its a bit of a puzzle this.. has there been any other changes in care of the tank? New kind of fish food, or change in amounts of fish food, or has someone else been feeding (could be feeding more) ? Plants do look very nice from what the pictures show..


During the 2 weeks I was away the fish were fasted. So instead of daily small amounts of food received maybe food 3/4 times in the 2 weeks. Guess they might have put more food in than normal but no fish died so was a success in that regard. Now im back to normal feeding regimen but the green slime is still there. No one else is feeding now as I have hid the food just in case lol Yes plants are still growing well and pearling fine and fish are healthy too. Just the annoying film at the top which actually gets green bubbles sometimes so i'm guessing it's some sort of algae. 


MichaelJ said:


> Hi @Animallover  Well, this certainly fall into the category where UV would help - if its a floating green algae problem its definitely worth considering throwing some UV at it and keep up those WCs until the problem goes away - I've recently fixed a problem with cloudy water with great success  (cloudy for other reasons though). It's puzzling that a short lapse in WC/maintainance would cause this - sounds coincidental to me... unless something was going on with the tank that you are not aware of while you were away - such as overfeeding, CO2 failure, switching off filtration by accident etc... Perhaps someone else can shed more light on this one.
> 
> If you deploy a UV filter, just make sure you switch it off for say 6 hours after dosing traces (Iron in particular).
> 
> ...


Okay I can try the UV filter thing then. There possibly could be overfeeding although the person feeding is denying anything so maybe not. Yeah could be the latter stuff but was all working as normal when I was back so unless there was a power cut and it just restarted I wouldn't know. 


Wookii said:


> Is the layer on the surface not just a typical protein surface scum, or is the first couple of inches of water affected rather than just the white slick on the surface?
> 
> If mainly the former, then a skimmer should get rid of it in fairly short order:
> 
> Amazon product



Yes there is a small layer of protein scum that is clear/whiteish which is fine. It's the green layer on the top that's a nuisance though and I've not had that before. When I do a water change there is maybe 5 finger lengths of green algae that sticks onto the aquarium glass along the whole perimeter and even after manually cleaning all of that after every water change it keeps coming back. 

Does the skimmer work in a different way to the UV filter? 


tiger15 said:


> I treated green water in my shrimp bowls with live daphnia.  They cleared up the water in few days and became shrimp food when they dropped dead after algal food is exhausted.  It works for me because I have a daphnia source from my outdoor tub culture and I have no fish to prey on live daphnia.  But I heard that you can protect  the daphnia in a brine shrimp net in a fish tank to do the job, provided that you can find live daphnia.


It does look like I can buy live daphnia online how many would I need though? And i'm sure my fish eat daphnia so wouldn't need to use the brine shrimp method you have suggested. 



Also, I done a water change today (about 10 hours ago) and always clear water the first 2 days and then the green algae begins again.


----------



## MichaelJ (12 Nov 2021)

Animallover said:


> Does the skimmer work in a different way to the UV filter?


The skimmer will suck and break up the protein scum and whatever is on the surface (I use the one @Wookii recommended in both my tanks - very good). A UV filter will kill the algae and spores floating around in the water column - it wont deal with the stuff already accumulated on the water surface. For "green water" (if thats the case) its very efficient indeed. How big is your tank? I would recommend the 9W or 24W Green Killing Machine (depending on tank size).

Cheers,
Michael


----------



## Animallover (12 Nov 2021)

MichaelJ said:


> The skimmer will suck and break up the protein scum and whatever is on the surface (I use the one @Wookii recommended in both my tanks - very good). A UV filter will kill the algae and spores floating around in the water column - it wont deal with the stuff already accumulated on the water surface. For "green water" (if thats the case) its very efficient indeed. How big is your tank? I would recommend the 9W or 24W Green Killing Machine (depending on tank size).
> 
> Cheers,
> Michael


Ok thanks for the explanation. The tank is 318L. Is one enough?


----------



## MichaelJ (12 Nov 2021)

Animallover said:


> Ok thanks for the explanation. The tank is 318L. Is one enough?


If you mean the UV Filter... I would go with the 24W model with a 318L tank (Yes, one is enough).  The 9W model would still work - It will just take much longer due to the lower turnover. The flow in these filters needs to be relatively low in order to ensure that the water that flows through the filter gets adequate exposure to the UV light.  When the problem dissipates you can choose to put it on a timer and only run it for a few hours a day - or take it out of the tank - using UV filters is somewhat problematic, as it also kills beneficial bacteria and breaks up certain fertilizers (such as Iron and render it ineffective) - and of course keeping it on a timer a few hours a day will extent the lifetime of the bulb tremendously (if you run it 24/7 the bulb will typically only last 6 months).  

For the suggested surface skimmer, I would do two in a 318L tank - they are relatively cheap, but one might suffice. With a lot of gunk on the surface be prepared to clean them often.

Cheers,
Michael


----------



## tiger15 (12 Nov 2021)

Animallover said:


> It does look like I can buy live daphnia online how many would I need though? And i'm sure my fish eat daphnia so wouldn't need to use the brine shrimp method you have suggested.
> 
> Also, I done a water change today (about 10 hours ago) and always clear water the first 2 days and then the green algae begins again.


Water change isn’t a solution for green water, and may trigger more by replenishing the minerals algae used up.  Green water is caused by excessive light and nutrients, and since you are dosing EI, there is no shortage of the latter, and excessive light is likely the cause. 

My shrimp bowls receive window sunlight, and once a year  in spring or summer, I got green water outbreak when things are out of balance.  By introducing daphnia dense enough my eye can see them dance around, the green water is cleaned up in couple days.  Daphnia feed on suspended algae (euglena), and will multiply if they are well fed or slowly die off from starvation.   I grow daphnia culture in outdoor tub filled with water change water in full sunlight that triggered green water food for the daphnia.


----------



## MichaelJ (12 Nov 2021)

tiger15 said:


> excessive light is likely the cause


Yeah, good point. @Animallover,  could it be that the timer or intensity of the light was tripped somehow while you were away so it was blasting much longer or stronger than usual?... Always good to know the root cause.



tiger15 said:


> My shrimp bowls receive window sunlight,


@tiger15 I think you posted about those shrimp bowls a while ago (I want to look into doing something similar) - was trying to find that thread again but couldn't. Might have been on a different forum. 

Cheers,
Michael


----------



## tiger15 (12 Nov 2021)

MichaelJ said:


> Yeah, good point. @Animallover,  could it be that the timer or intensity of the light was tripped somehow while you were away so it was blasting much longer or stronger than usual?... Always good to know the root cause.
> 
> 
> @tiger15 I think you posted about those shrimp bowls a while ago (I want to look into doing something similar) - was trying to find that thread again but couldn't. Might have been on a different forum.
> ...


I don’t have a thread on my shrimp bowls but posted replies to other posts on my experience of zero tech set up.


----------



## MichaelJ (12 Nov 2021)

tiger15 said:


> I don’t have a thread on my shrimp bowls but posted replies to other posts on my experience of zero tech set up.


Yep thats the one I couldn't find. Thanks.


----------



## ceg4048 (18 Nov 2021)

Animallover said:


> Hi guys,
> 
> I was away for 2 weeks and no one I live with were happy to do weekly water changes. During this time EI dosing was continued and no other changes except for 1 missed 50% weekly water change on day 7 after I left. When I returned the water looked less clear than usual (nothing crazy but noticeable) but the main issue was on the top there was a film of algae floating completely on the surface of the water not attached to anything in particular. I done 3 big water changes over the next week and continued everything as normal. The water is completely clear for the first few days post water change but by the time its day 7 it just has that semi green tinge and the layer at the surface of the water. It's not the end of the world as still looks fine but I do prefer crystal clear looking water throughout the 7 days prior to water change as before.
> 
> ...


Hello,
         The root cause, as usual, is a CO2 deficiency which may not affect all the plants, but probably somewhere in the tank there is a deficiency. This may have been the result of the plants growing and causing blocked flow or blocked distribution.
The green organisms at the surface, as mentioned are a combination of algae and bacteria feeding on the proteins in the scum. Sometimes they are green and other times they are brown. More information in this thread=> Surface Film

There is no problem with EI and UV lighting. Having said that, UV will not fix this problem. Only when the entire water column is green do you actually have a green water algae problem.

Cheers,


----------



## MichaelJ (19 Nov 2021)

ceg4048 said:


> The surface of the water can have green or brown things floating on it and the light, shining through those things can cause the rest of the tank to _appear to be _green or brown.


That makes total sense. My tanks surfaces are almost covered in duckweed and frogbit and the water column do actually appear _slightly_ greenish because of that. Darn it!   I should have thought of that answer.

Cheers,
Michael


----------



## John q (19 Nov 2021)

ceg4048 said:


> We cannot control what others have heard of


Socrates 392 BC?

Classic... Hope you don't mind Clive, but I'm pinching that quote.

"I will not make any deals with you. I’ve resigned. I will not be pushed, filed, stamped, indexed, briefed, debriefed, or numbered. My life is my own."

Move on, nothing to see here 🙉


----------



## MichaelJ (19 Nov 2021)

John q said:


> Socrates 392 BC?


Was he in The Matrix ? 


John q said:


> I will not make any deals with you. I’ve resigned. I will not be pushed, filed, stamped, indexed, briefed, debriefed, or numbered. My life is my own.


The Prisoner ?  Patrick McGoohan - he turned down an offer to play James Bond for a role where he could ride a kit car.... go figure.

Cheers,
Michael
​


----------



## John q (19 Nov 2021)

Yep


MichaelJ said:


> Was he in The Matrix ?
> 
> The Prisoner ?  Patrick McGoohan


Haha yes , forward thinker, Danger man, well ahead of his time, perhaps the prequel to The Matrix 😁


----------



## tiger15 (20 Nov 2021)

Free floating is a misnomer.  Green water is made up of Euglena, flagellated single cell photosynthetic eukaryote.  They are suspended in water  and capable of free swimming.









						Euglena - Wikipedia
					






					en.wikipedia.org


----------



## MichaelJ (20 Nov 2021)

tiger15 said:


> Free floating is a misnomer.  Green water is made up of Euglena, flagellated single cell photosynthetic eukaryote.  They are suspended in water  and capable of free swimming.
> 
> 
> 
> ...


@tiger15   Interesting info. Thanks for posting.


----------



## rebel (20 Nov 2021)

I once had a green water problem. I paid $80 for a UV unit. Within one day the problem was gone. I have never had to use the UV since. I suggest you borrow the UV unit for one week and pay the owner $10.


----------



## ceg4048 (23 Nov 2021)

John q said:


> Socrates 392 BC?





MichaelJ said:


> Was he in The Matrix ?


He and I spoke briefly. We met in a phone booth.
Along for the ride were Bill and Ted. It was their Excellent Adventure...

Cheers,


----------



## rebel (23 Nov 2021)

? phototropic maybe.


----------



## MichaelJ (23 Nov 2021)

rebel said:


> ? phototropic maybe.



Very fascinating footage. Makes you wonder what exactly constitutes complex if not intelligent life - albeit microbial. Some of these guys totally look like they are on a mission - while others just bounce around randomly.


----------



## tiger15 (23 Nov 2021)

*Euglena are complex single cellular organisms with multi functional organales.  They evolved much later after the first photosynthetic cynano bacteria have been in existence for a billion year.

*


----------



## rebel (24 Nov 2021)

If the OP truly had an outbreak of Euglena, then increasing CO2 could make it worse?

It looks like Euglena can use CO2 to photosynthetise....?


			https://www.ijert.org/research/co2-sequestration-and-growth-characteristics-of-euglena-gracilis-in-a-photo-bioreactor-IJERTV2IS110415.pdf
		


This might be especially true if they can occupy the upper parts of the tank and starve the plants in the lower parts of light, CO2, and maybe even O2. This assumes that flow is unevenly distributed, which it is in my tank due to the hardscape design.


----------

