Brown Algae/diatoms

[rhian]

Hello

I have been getting on well with my planted tank, the plants are growing well & the fish seem happy - I have started to notice some brown diatoms/algae mostly on my anubia leaves, I read that this is common with new tanks - will it go away naturally? or should I do something about it?

It is a low tech tanks, similar to a Walstad type tank. There is indirect light from a north facing window, and 20w of fluorescent light from a T8 lamp in the lid. The light is on 12hrs a day - is that too much?

I have 4 lemon tetras, and have just added 3 platies. The tank has been going since mid july. I feed the fish every other day, and only added fertiliser when there were no fish present.

Many thanks

 

[RadaR]

What fert were you dosing?
Diatoms are common in new tanks because of ammonia readings. Even when the readings are undectecable, the ammonia can still cause diatoms. So we want good growing plants and goof filtration to take care of the majority of ammonia.
Your lights are on for too long. Cut it down to 7hours a day. Things should start clearing up. Manual removal is advised

 

[awilson360]

What fert were you dosing?
Diatoms are common in new tanks because of ammonia readings. Even when the readings are undectecable, the ammonia can still cause diatoms. So we want good growing plants and goof filtration to take care of the majority of ammonia.
Your lights are on for too long. Cut it down to 7hours a day. Things should start clearing up. Manual removal is advised

My goldfish tank finished cycling about 4 weeks ago and in the following weeks the Brown Diatom Algae became hidious! I decided to manually remove it all and then rinse out the filter in tank water and do a large water change and everything is fine now, a week later no more brown algae!
I keep my light on for about 9-10 hours a day and its only 1 WPG, better to let the plants consume as much nitrate as possible to prevent excess causing Algae growth.

AW

 

[RadaR]

It's key to understand that the ammonia and light triggers the algae. If the spores get enough of each, then the spores will bloom. Then yes they can use nitrates as food. However the algae wouldnt be there in the first place if it wasnt for the ammonia. Would we stop dosing nitrates? No. That would make problems worse because the plants would starve, leach more ammonia and thus cause trigger more spores. Keep the plants happy and give them what they want in combination with limiting ammonia and the spores should never bloom.

 

[rhian]

Hi, thanks for the advice. I wiped off what diatoms I could, the anubia leaves were a bit slimy and there seems to be brown patches or stains underneath. I changed the timer to 7 hours.

I am using Tropica Plant Nutrition plus (TPN+), so should I dose 3 times a week? and when should I increase the light again? (I was thinking of adding flourish excel)

Some of my amazon swords have brown patches on the leaves, and some of my twisted vals have some soggy dead leaves, but they seem to be regrowing from the base. I think as they were all bare root, the older leaves died off. The brown marks, is that potassium deficiency? the leaves are otherwise a nice green. The aquarium is heavily planted, I was following the Walstad idea, so should I be changing the water much? it's very clear at the moment, but the fish have only been in 3 weeks.

many thanks

 

[RadaR]

Don't turn the lights up. That's the last thing you want to do if you are already experiencing algae.
Generally the Walstad method is very low tech combined with low light so macro nutrients typically dont need to be dosed regularly. Your plants do seem to be telling you though that something is missing.
Try doing a 10% water change every other day and dose TPN+ straight afterwards. 2weeks time is enough time to see a difference. If you dont then we'll have to look towards something else.
Oh, when you do the water change, make sure it's before or after the photoperiod, not during

 

[rhian]

thanks, I'll get on with the 10%water change tomorrow

the new leaves look ok, it is the older leaves + the diatoms on my anubia. Luckily they're not on the glass or many leaves at the moment, so hopefully caught it in time as there must be spores! I did go for low light plants, well assuming I chose the right ones (crypts, 1 anubia, sagittaria, amazon swords, java ferns, twisted vals, a water lettuce on the surface plus 3 moss balls)

will the fish mind less light? I was thinking of buying an led nightlight to see the tank when the main light is off.