# Struggling with Brown Algae



## bjorn (5 Oct 2011)

I've been struggling with Brown Algae on plants, glass and rocks in a mature tank. On the plants it's always the lower leafs that are affected. Rocks are just covered in it and instead of seeing the nice grey/purple colouration of the Manten stone it's just a brownish color (If I scrub the stones the brown algae comes off easily).

I have no other signs of any other type of algae except maybe a tiny amount of green spot algae on the upper parts of some wood that's just by the water surface. I expect that's because it's so close to the light.

The affected plants are mainly stem plants which are situated where the highest amount of flow is, they are all swaying in the current and got plenty of space around them. For some odd reason the larger plants in lower flow areas (Echinodorus) are not affected it seems.

I'm dosing daily with 8ml TPN+, 5x drops of ECA and 5ml Excel every other day. 

I have moved about some plants a few times over the last month, which each time has disturbed the substrate. 

Tank and Equipment:
- 170L / 50g tank
- 3 x AquaRay GroBeam 1000 ND LEDs (PAR reading at the bottom of the tank is around 80-90)
- Inline CO2 reactor
- Fluval G6 (2460 lph / 1000lgh) 

Values

PAR: 80-90
PH: 6.50
CO2: LimeGreen / Yellow
NH3: 0
NO2: 0
NO3: 10-20ppm
PO4 Tank Water: 0.3-0.4ppm
PO4 Tap Water: 1.8+ppm
KH: 12
GH: 18

I only today measured PO4 for the first time and noticed the huge difference between my tap water and tank water. Is there any chance that High PO4 in the water I put into the tank can cause this problem?

Or could it be that I have too low light?


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## gargamelcz (14 Oct 2011)

Hi,
I'd try to get more fertilizer into tank water and CO2 in your case. I had the same problem. I increased an amount of CO2 gas in the tank and problem was solved. But in your case, I'd try to add KH2PO4 into your tank too.


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## Matt Warner (14 Oct 2011)

Hi,
As above keep the tank well fertilised and make sure you have good flow around the whole tank. Are all of the plants gently swaying in the current?


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## Matt Warner (14 Oct 2011)

The high P04 won't cause brown algae. How often do you perform a water change and how much water do you change? Disturbing the substrate too much can cause particles of debris to settle on the leaves and cause algae. Always try and do a water change after disturbing the substrate too much
Cheers


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## ceg4048 (15 Oct 2011)

bjorn said:
			
		

> I've been struggling with Brown Algae on plants, glass and rocks in a mature tank.
> 
> - 3 x AquaRay GroBeam 1000 ND LEDs (PAR reading at the bottom of the tank is around 80-90...


This is the reason.
Try reducing this value by 50% at least. There's no point having a PAR meter if you ignore the readings. Diatomic slgae is caused by too much light.

Cheers,


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## bjorn (18 Oct 2011)

ceg4048 said:
			
		

> bjorn said:
> 
> 
> 
> ...



I read some other threads that indicated that up to 90PAR was medium light.. is that totally incorrect then? What PAR should I aim for?

I also just tested my tap water for Silicate (SiO2) and it's off the chart with 6.0+ppm. I also did the same test on some RO water and it's got 0ppm.. so not a problem with the test kit.


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## GHNelson (18 Oct 2011)

Hi Bjorn
Its definitely to much light....how long do you have the lights on for?
Regular water changes will help clear this up.
Buying some Otto's will also help....as they like this sort of algae.
Cheers
hoggie


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## bjorn (18 Oct 2011)

So annoying, I made sure to read up about it and on another forum there was along discussion about PAR readings and of course it's the wrong one to follow.

I have the lights on for 9 hours per day, with 1 hour ramp up on each side.

I also have a couple of Otto's but it's far too much for them to even make a difference.

What PAR reading should I aim for then?


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## GHNelson (18 Oct 2011)

Hi Bjorn
I wouldn't take much notice of Par readings as your plants and aquarium will tell you if you don't have enough light.
If i were you I would do either one of these two things.... reduce your lighting to 6 hours immediately.
4 hours then ramp up the lighting for 2 hours.
Monitor this and see if it reduces your brown algae..... do regular water changes.
Or just reduce the lighting intensity by 50% as Ceg stated.

When brown algae appears in a mature aquarium its usually down to to much light and not enough attention to good house keeping....that includes regular water changes....that's just my observations.

When i cant be bothered or don't have the time to keep on top of the water changes with one of my plant only tanks and i'm also using too much light......... brown algae usually pops it head up.
First thing I do is do a 95% massive water change and gravel clean......reduce the lighting.
Hope this helps.
hoggie


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## bjorn (18 Oct 2011)

How do you tell when there isn't enough lights? See some sites I've been reading says Brown Diatoms goes away with higher light.. I assume that's entirely wrong.

I do regular water changes, 50% once a week. Filter also kept tidy. I'll have to try and reduce the light and hope for the best then.


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## Fred Dulley (19 Oct 2011)

bjorn said:
			
		

> How do you tell when there isn't enough lights? .



The plants dont grow despite you giving them heaps of CO2 and nutrients (and flow).
If the light was well, well under the light compensation point (LCP) then they'd degrade.


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## GHNelson (19 Oct 2011)

Hi Bjorn
There may be a clue here :arrow: you quoted
For some odd reason the larger plants in lower flow areas (Echinodorus) are not affected it seems.
Is that because there is less light :?: 
Cheers
hoggie


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## bjorn (19 Oct 2011)

hogan53 said:
			
		

> Hi Bjorn
> There may be a clue here :arrow: you quoted
> For some odd reason the larger plants in lower flow areas (Echinodorus) are not affected it seems.
> Is that because there is less light :?:
> ...



They would have had more light than the rest, they are very tall and almost reach the surface.


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## bjorn (4 Nov 2011)

Bit of an update. I lowered my lights on the new setup to PAR38 at the substrate. Not had any issues at all with brown diatoms or any other algae at all. Not even on the glass. Just hope it stays the same but it's now been ok and clear since 19 Oct (2+ weeks).


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## bjorn (6 Nov 2011)

I spoke to soon. Some diatoms are back, mainly on some of the rocks. This is with low light, correct fertilizer regime, good co2, circulation etc.. Still just comes back no matter what I do. I'm also using 50/50 RO water now. Driving me nuts and don't know what to do.

SiO2 (silicate) measurement is off the chart at 6+ppm
PH4 is 0.2ppm


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## tyrophagus (6 Nov 2011)

Bjorn I have the same lights. My par is closer to 25 at substrate level. I'd reduce your lighting. Worse that can happen is things grow slower or slowly die. You can always turn them up slowly.


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## bjorn (6 Nov 2011)

*Re:*



			
				tyrophagus said:
			
		

> Bjorn I have the same lights. My par is closer to 25 at substrate level. I'd reduce your lighting. Worse that can happen is things grow slower or slowly die. You can always turn them up slowly.



Lower? Don't you find it starts to look very dim at even lower level? Mine is now set to 33% power. Maybe I should raise the lights further up rather than lower the power?

What PAR is good to aim for then?


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## tyrophagus (7 Nov 2011)

I have 2 tiles on a 90x45x45. They are about 25cm from the surface and I have the intensity set at 75%. I have a 30min ramp each side of a 6 hour lighting period. 

From previous discussions I think a PAR of 30 is considered ok at substrate. 

If there's one thing I've learned in the last 2 yrs in the hobby it's that less light is better when it comes to algae.


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## bjorn (8 Nov 2011)

*Re:*



			
				tyrophagus said:
			
		

> I have 2 tiles on a 90x45x45. They are about 25cm from the surface and I have the intensity set at 75%. I have a 30min ramp each side of a 6 hour lighting period.
> 
> From previous discussions I think a PAR of 30 is considered ok at substrate.
> 
> If there's one thing I've learned in the last 2 yrs in the hobby it's that less light is better when it comes to algae.



Thanks for sharing. I've lowered mine further. I think I would have been fine with just 2 tiles, having 3 at 30cm means I run them at 30% now and get PAR 32-34. Will see how it goes.

Just a bit frustrating as I don't have any other algae problems at all. Just these diatoms hanging about. Have had more growth of it on the glass now as well so coming back for sure.


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## Alastair (9 Nov 2011)

Doesn't high silicates contribute to brown algae?


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## tyrophagus (9 Nov 2011)

I had a problem with diatoms as well, started covering all my plants. I was looking at some tanks at Aquajardin in gloucester and it struck me how "bright" my tank was.  I lowered my par to about 25. The algae cleared and I have raised the PAR to 30

Drop your par level further for a week or two. Go lower than you think you should then if that does not work you will have to look elsewhere. 

It's like cooking. You can always add more salt.


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