Major Tank Issue - Massive Algal Growth, Plants Dying, Help!

Hello and apologies for the dramatic title, but things have gotten very worrying in the last week or two and it's causing me no end of stress! This is my first tank, and it has been operational for 7 weeks now (including cycling). To begin with, I had some algae growth on the wood surfaces and plants in the aquarium, but it calmed down after a week or so. In the last couple of weeks however, it has gone haywire! The amount of hair algae on the moss and some of the plants is ridiculous, and some kind of algae growth has killed off a large chunk of stem plants on the right hand side of the tank! I don't know what to do, and don't want to see the tank fall into ruin...

As you can see in these images, the hair algae has grown out of control here. I've tried picking it off with tweezers to slow down its growth, but it hasn't worked well.




In these photos you can see the right hand side of the tank. The plants you see in the fist image were originally found on both sides of that piece of wood, the same height! they grew amazingly since they were put in, over tripled in height! However in the second image, you can see whats left of the one bunch on the left. That happened in just over a week. And in the third image, you can see the early signs of the same issue on the bunch on the right. It started like that about halfway up the plants, then spread up and down until the parts just rotted and died.... I have no idea what to do!


Some facts about the tank: It is a UK 125l tank (80cmx50cmx35cm). The water parameters are normal (0 ammonia, nitrite/nitrate). I keep it around 24-25 degrees C, and fertilise with both seachem flourish root tabs, and once weekly with a half cap of seachem flourish liquid fertiliser (not excel). the lights in the tank are the Fluval Aquasky ones that came with it, and I have it on a timer for 7 hours a day on full, with an hour either side to wind up/down respectively so as not to shock the fish with sudden light changes. I change 40-50% of the water once weekly. Any help would be appreciated, as I have no idea what to do....

Horrible stuff .I feel your pain ! I've had to dump an replant a few times because of algae . Bleach dip brought mine back like new . But some of them died off after it . Some of the experts will know more about that . Your setup sounds good. Similar to mine now . So not sure why your getting that growth . Is your tank near a window ?

In addition to the algae issue, I've had real trouble keeping the plants healthy! While some have grown really well, others have really struggled, even those which are supposed to be the hardiest of the lot!



I have several bunches of Java Fern in my tank, and all of them are dying, as can be seen most clearly in the image above. As i've stated, I dose with liquid fertiliser, so I don't understand what the problem is there. In addition, plants like my Amazon Sword which have been supplemented with root tabs have been doing poorly as well, with the image below displaying how pale and mottled they look.

There is also plants like my Anubias near the front which are coated in some kind of algae (?) and look quite unwell also....



Any advice would be appreciated..

Brendanpat said:

Horrible stuff .I feel your pain ! I've had to dump an replant a few times because of algae . Bleach dip brought mine back like new . But some of them died off after it . Some of the experts will know more about that . Your setup sounds good. Similar to mine now . So not sure why your getting that growth . Is your tank near a window ?

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Thanks for the response! As for the window, there is one about 2-3 metres way but it never gets direct sunlight, and only shines on one edge of the tank which isn't the one with the issues, oddly enough!

Derigriff said:

Thanks for the response! As for the window, there is one about 2-3 metres way but it never gets direct sunlight, and only shines on one edge of the tank which isn't the one with the issues, oddly enough!

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Same as mine .mine went through a phase of that hair algae. That's when I done the bleach dip. Watched it on YouTube. Had to change my light and added floating plants and fast growing elodea densa . Still working on it !

I've got a bunch of floating plants, ranging from Water Sprite, Water lettuce, and some of what I assume is duckweed or some such that snuck in. Most of them seem to be dying too, or at least the Water Lettuce is melting. Though that could partially be due to the fact that the surface movement clumps them all together somewhat.

Derigriff said:

I've got a bunch of floating plants, ranging from Water Sprite, Water lettuce, and some of what I assume is duckweed or some such that snuck in. Most of them seem to be dying too, or at least the Water Lettuce is melting. Though that could partially be due to the fact that the surface movement clumps them all together somewhat.

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Strange . So the plants aren't using the nutrients so the algae is having a field day .wonder why ..I'm dosing 1.5ml of seachem flourish comprehensive in my 105litre . It seems to be enough .experts will be along soon I'm sure

Brendanpat said:

Strange . So the plants aren't using the nutrients so the algae is having a field day .wonder why ..I'm dosing 1.5ml of seachem flourish comprehensive in my 105litre . It seems to be enough .experts will be along soon I'm sure

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Algae is a is a single cell orgainism. Each Cell is microscopic and at that size it doesn't need a lot of nutrients to grow. Plants however are multicelluar and therefore much larger. So plants need signify more to grow. So basically your water is deficient in at least one of 14 nutrients plants need to grow. A deficiency in any one nutrient can cause the plant to die. But the deficiency is not strong enough to affect the algae so it is taking over the tank.

surface motion in most cases will not kill your floating plants. Floating plants get all the CO2 they need from the air. So it is not CO2 and based on your pictures you have sufficient light for growth. So you are missing any one or more of the following in your water:
Nitrogen, Potassium, Calcium, Magnesium. Phosphorous, Sulfur, Cl (as a chloride salt not as a gas or chloramine), Iron, Manganese, Boron, Zinc, copper, Molybdenum, Nickel.

Look at your bottle do you see anyCalcium? How hard is your water? Also note your fertilizer likely doesn't have enough Magnesium. If your water is very soft increase the hardness with A GH booster.

Derigriff said:

The water parameters are normal (0 ammonia, nitrite/nitrate).

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Zero nitrogen is also a deficiency Keep nitrate no lower than 5ppm. You want Ammonia and nitrite at zero.

there are likely more issues but start with the these

I've stopped using my tank light, I'm only relying on ambient light from windows and room light. it has definitely curbed the algae growth for me.