Algae problem after new light

[aHumanError]

Goodevening everyone.

New to the forum, not really a beginner fish-keeper but I've not really had many issues up until recently.

So... the story is that I have a 64L tank, and for the past 4 or 5 years I had a twin LED light (pic attached) which was an upgrade (From a "biult-in" single) for my tank at the time. I had no problems with it until the LEDs started burning out.

Typically I couldn't find a direct replacement so I found a different twin LED light ("Interpet") that I thought was similar... and it was the worst thing I ever bought for my tank. After about a week I had an algae explosion. I'm not all up on algae but It was long green hair like algae that grew all over the plants, I couldn't remove it other than to take off the leaves. I tried reducing the hours the light was on (It's on a timer) and upped the water changes but it just seemed constant.

After 4~5 weeks the algae turned into some dark green slime which grew on everything, it resembles something from the blob... or slimer out the Ghostbusters. The good thing is it's much easier to remove from plants, bad things is this stuff seems to grow at a phenomenal rate, and basically ruined all my plants and made the water smell.

So rather than going on the hunt for another light that could end up making no difference, and spending more money (Because let's face it, for what they are they're pretty expensive) I had an idea and wired in a small potentiometer circuit I had laying about that would allow me to reduce the brightness of the light.. which I did by about 50%. I also done a 50% water change and removed and cleaned everything.














This was around 4 days ago and already the damn algae has already grew back on the substrate and some leaves (on what's left of the plans). Initially I blamed the light for being to intense, but now I'm starting to think it's something else, but then at the very least I'm pretty convinced the new light caused it. I've not had to test my water for years, I recently did this and all results seem normal, I even took a sample of my water to some local fish store that also does free tests and they too say it's fine.

So I'm unsure as to where to go next, it still seems to be appearing despite all my efforts. I'm sure someone who knows what I'm doing wrong can help

 

[Seisage]

Well, I can tell you that the green slime did not come from the algae already in your tank, but is in fact something completely different that’s now growing alongside it: cyanobacteria. From what I understand, the recommended remedy for both algae and cyanobacteria is still to just do frequent manual removal and large water changes.

One thing you might want to look into is the color balance of your lights. I’ve heard that algae greatly prefers blue light, so if there’s a lot of blue in the LEDs you’re using (either in color tone or actual blue diodes), it may be that. The solution would be to reduce blue spectrum light and increase red light.

 

[aHumanError]

Well, I can tell you that the green slime did not come from the algae already in your tank, but is in fact something completely different that’s now growing alongside it: cyanobacteria. From what I understand, the recommended remedy for both algae and cyanobacteria is still to just do frequent manual removal and large water changes.

One thing you might want to look into is the color balance of your lights. I’ve heard that algae greatly prefers blue light, so if there’s a lot of blue in the LEDs you’re using (either in color tone or actual blue diodes), it may be that. The solution would be to reduce blue spectrum light and increase red light.

Thanks for your response.

What you say about this cyanobacteria makes sense because the new light has 2 "modes" via a switch (3 if you count off). The first just shines blue LEDs (I've never been sure why aquarium lights insist on including blue lights... perhaps aesthetics?), and second is blue AND white LEDs shine together... and from what you say it's a bit of a problem.

I suspect the blue light is amplifying the issue I'm having. If I was to keep this light I think I'd be able to modify it yet again to drop the blue LEDs, but it may be easier to find a new light all together which just has white light only.

It's annoying not only because of the changes I've already made but more the fact that I had to slightly modify the lid to fit this peace of garbage. I wish I knew this before.

 

[MaloK]

Need more detail on your Setup: Size, filtration, plants, fish.

If the light you have is not programmable, and you cannot control all the colours and power it emits.

Consider getting a full blown... I found pretty neat ones for low $... "too powerful" but they can be controlled.... Or... Put duck tape to blind them. I mean you can play with things like that. Never really refrained to try, and sometimes...

If you can also get a hold on cheap floating plants ? It could change everything. Or start to get algae on them...

Dissolution is the solution. Make partial water changes and reduce light period until Your Algae recess.. Even a couple days in the dark as a hit dose and water changes everyday Can reverse a sliding tank.

 

[outofwater]

If you can tweak the blue light intensity go for it. I went thru something similar with a hygger unit. I've tweaked the brightness and timing and that stopped the spread, but it hasn't completely gone away, and I have a feeling that it's due to the setting for "moonlight" which activates only the blue lights for the last portion of the daily schedule. While I thought it'd be cool and good, it seems to be feeding the algae and I'll get to it this weekend to see how that goes.

 

[Colin_T]

It's blue green algae (Cyanobacter bacteria). It loves red light, nutrients, slow water movement and low oxygen levels.

Light should be white LEDs, which hopefully give you a 6500K rating.
Red light has a lower Kelvin rating (4000K)
Blue light has a higher Kelvin rating higher (8000K+)