Green / Blue Algae Collecting On Substrate & Plants

[Carey27]

I have a planted tank and over the past 2 months or so a greenish / bluish layer of algae has been popping up. It grows or appears on some of the plants, but mostly builds up on my sand substrate.

Just cleaned the tank last week and its building up on the bottom again. Any info/advice?

 

[scouse_andy]

Most people will say try some antibiotic tablets.

Instead I tried a complete blackout of the tank for three full days, no feeding, no peeking.

Worked a treat. I was almost blinded with how light the tank looked after weeks on end of dark algae. As soon as I'd uncovered the tank I took all the water, plants and substrate out (inert silica sand) and replaced with a nutrient rich substrate (soil) with a layer of sand on top and replanted.

Since then I have no sign of the BGA. A lot of brown diatoms as the water was all new though, but I hope this will clear.

The point is that a blackout may well work but unless you get to the root (haha) of the problem and sort it out, the algae will probably return at some point soon. Make sure you have plenty of fast growing stems to use up nitrates and phosporus.

Hope this helps

 

[Maximus]

I did exactly what was mentioned above ^^

See the results for yourself...

http/www.fishforums.net/index.php?showto...96&start=96



Maximus

 

[Carey27]

Thanks,

I was thinking about using Maracyn tablets (as per one of the stickied algae articles) but I'm a little worried that this might kill the good bacteria that exists in my filter. Any thoughts on that?

 

[scouse_andy]

I was thinking along the same lines but the blackout and change of substrate has worked so far (fingers crossed)

Why do you think the algae has started? What's you WPG? co2? planting density etc? what substrate do you have?

 

[Carey27]

I was thinking along the same lines but the blackout and change of substrate has worked so far (fingers crossed)

Why do you think the algae has started? What's you WPG? co2? planting density etc? what substrate do you have?

I have low WPG (~1). Substrate is sand, neutral pH, I havent checked the CO2 in a while but i have a nutrafin kit.

My plants are dark green low light plants (Swords, java fern, a plant that sounds like canibas, and a wisteria that was thriving but appears wilted now). Density used to be thicker but i removed some plants that appeared to be "wilting"

 

[scouse_andy]

I'm no expert, maybe someone who knows a bit more will be able to help you out too.

I think maybe you should add a higher density of plants, thjings like elodea and hygro polysperma to eat up all the excess nutrients and perhaps also change substrate, It is a pain to have to strip down the tank and restart in a way but I definitely don't regret it myself.

 

[Carey27]

Im planning on picking up some hygro & Maracyn tablets today so hopefully that will work. Ill keep you posted

 

[Dave Spencer]

If it is BGA, you may be interested to know that it is not a form of algae, but is actually bacterial.

If I remember rightly, it can be caused by anaerobic spots in the substrate. I sometimes get a little film of this stuff at the front edge of my tank which has a sand substrate. Sand is supposedly particularly susceptible to anaerobic pockets. Low nitrates can also be a cause.

Anyway:
Remove as much BGA as you can.
Feed your fish.
Knock the CO2 off.
Carry out a 50% water change.
Cover the tank in a thick blanket, totally blocking out all light (no peaking).
Remove the blanket after three days.
Carry out a 50% water change.
Reinstate CO2 and whatever fertilisers you use.

Note: you may what to take the precaution of aerating the tank during the blackout by rippling the water surface with the filter outlet or using an airstone.

You may also want to start a regime of gently agitating the substrate once a week to prevent anaerobic pockets forming again. I have a little army of Malaysian Trumpet Snails burrowing through mine.

 

[Musho3210]

love malaysian trumpet snails..... They sift my sand nice and clean.

 

[JamesC]

Why buy anti-biotics to put in your tank when there is a much quicker, more effective and cheaper method - The 3 day blackout. You will need to address the cause of the outbreak otherwise it will probably just reappear whichever method you use. Normally it's very low nitrates. BGA hates potassium nitrate. I've seen it in new setups as well where ammonia and nitrite levels have been quite high.

It is also very common to have BGA in the substrate. Nothing to worry about as long as there are nitrates in the water column. Indeed I've had it in my tank for years now and it's never dared show it's head above the substrate.

More info is at - http/www.theplantedtank.co.uk/algae.htm

James

 

[Carey27]

Thanks for all the responses. Two quick questions:

Musho,
Great idea, but where can i get Trumpet snails? All teh snails sold at my LFS are NOT plant friendly...

James,
Thanks again for the info. I have a pretty well stocked tank (10 fish in a 30 gallon), what would cause the low nitrate levels? I thought the urea from the fish would begin the nitrogen cycle and result in nitrates. Is that a misunderstanding? And how can I increase the nitrogen levels?