# Is 200+ PAR causing problem?



## Kezzab (11 Mar 2016)

Despite doing just about everything that i've read to address this, i'm persistently getting staghorn algae and some GBA.

The staghorn is mainly affecting Juncus Repens, and to a lesser extent the Weeping Moss. It is not touching the Rotala or Hydocolyte or Crypts. Trying to pick it off with tweezers is a pain in the blahblahblahblah!

The GBA is only affecting the Juncus Repens.

Tank specifications - 15l
Lighting - Azoo Flexi-mini LED, on from 5pm to 10pm, tank sits on an east facing window ledge so gets some light all day, but not direct sun.
CO2 - Pressurised, from 7am to 8pm
Filtration - internal, claimed 100lph, cleaned weekly, spray bar
Fertilisation routine - EI
Water change - 2 x 75% a week

Fauna - 6 cherry shrimp, 3 amano, numerous juvenile Ramshorn snails (i think, they just appeared).

This http://www.theaquaticplantsociety.org/flexi-mini-nano-led-follow-up/ reckons the Flexi mini puts out 203 PAR at 2inches (presumably below water surface). In practice the light sits one inch above the surface of the water and the Juncus Repens and Rotala touch the surface, so i presume the PAR is even higher than 203. I've read George Farmer on here calling 250 PAR "insane" for a planted tank.

So for all that it's a pretty simple question:

Do i have too much light?

I cannot dim the unit. So options would be to raise it (which will require some DIY) or cover some of the LEDs, my guess would be that raising it would be preferable to get an even spread of light?

Sorry this is no doubt an old chesnut.


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## Kezzab (11 Mar 2016)

Whoops, fell foul of the profanity filter. Knuckles rapped.


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## ian_m (11 Mar 2016)

Not a particularly bright or efficient light, easily beaten by T5 lighting (this LED 75lm/W, T5 HO 90lm/W) as only using small LED's.

However your algae issue will not be helped by such a bright light, illuminating part of the tank.

Staghorn is often caused by low CO2 or poor CO2 distribution and/or in conjunction with poor filtration and/or dirty tank. Sorting the CO2 and dirt issue and treating with Excel/liquid carbon will sort it (and lower light level) but be careful with shrimp about.



Kezzab said:


> The GBA is only affecting the Juncus Repens.


 I assume you mean BBA (Black Brush Algae) ? Again indication of poor CO2 or poor CO2 distribution. Fix CO2 levels (and lower light levels and treat with liquid carbon.

Looks like the light unit takes just 12V, so you might be able to find a 12V dimmer module and wire it up to reduce light levels. (or use tape across the light). Of course once your issues are sorted (CO2 looks like main one) you can ramp the light level up.

If doing CO2 correctly, you only really need it on 2 hours before lights on and off 1 hour before lights off.


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## Dr Mike Oxgreen (11 Mar 2016)

Are you sure you can't dim the light? Just because it doesn't have that capability out of the box doesn't mean to say it can't be done!

Most LED controllers work by "pulse width modulation" (PWM), which means they switch the LEDs on and off very fast (so fast you can't see it), and vary the apparent brightness by altering the width of the 'on' pulse. It's almost certain that your light would work perfectly with a PWM controller, although you might need to cut its power cable so that you can solder appropriate plugs into it so that you can plug it into the controller. You can buy the plugs and sockets in Maplin or other electronics shops.

This is what I've done for both of the LED light units on my 25 litre tank, so I can now run them at whatever percentage I like and have them fade up and down over a configurable period at the start and end. Neither light unit officially 'supports' dimming out of the box, but it works very well!

That said, the specs for your light say 675 lumens, which seems like a generous amount of light for a 15 litre tank but it needn't be excessive. I'd still want to use an LED controller for full control though.


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## tim (11 Mar 2016)

Had the same light over my mini m, I used a strip of baking parchment cable tied over the LEDs, diffused the light and algae issues over.


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## Kezzab (11 Mar 2016)

Thanks for the replies.

I was aware of the dirty tank and co2 angles and to be honest i thought I had that covered. 2x 75% WC a week + weekly filter cleaning seems a pretty clean regime, but hard to know. I'm considering upgrading the filter to an Eheim Aquacompact 40, but it's a few quid...

In terms of the C02, the extended 'on' period was because of the amount of daylight hitting the tank, I didn't think it would do any harm. I can't see how distribution can be a problem in such a small tank (particularly as the worst effected plant is closest to the diffuser and i can see it swathed in co2 bubbles) in fact the 'dead spot' of the tank would be where the rotala is and there's no problem with it. But i'm new to this so i'm probably missing something.

The GBA i referred to was Green Beard Algae (as described here: http://www.aquariumalgae.blogspot.co.uk/) although it's perhaps what he calls Fuzz Algae, hard to say.

Re dimmers, soldering is not my strong point... would this work http://www.amazon.co.uk/JnDee-Inline-Dimmer-Controller-Suitable/dp/B009S4SDNA ?

I like the baking parchment idea, but rather ruins the look of an £80 light! 

Cheers.
K


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## foxfish (11 Mar 2016)

2 x 75% is more than enough but do you waft the plants around just before the water change?
Anyway the tank looks pretty clean to me


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## alto (11 Mar 2016)

Just note that either option will void any light warranty ... I'd try blocking the ambient light for a couple weeks & observe effect

Take a look at Marcel's The Stove journal - he mentions algae that pretty much reappeared only a few hours post water change ... you might also try daily water changes rather than twice weekly (if possible)


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## DanM621 (12 Mar 2016)

Personally, 2x 75% w/c per week is far too much water to be changing in a system on a regular basis. I know its a tiny tank with little volume but there isnt a lot of bioload in the tank to warrant that much water change every week. I'd recommend trying to reduce down those waterchanges to 2x 10% to get some stability in the water chemistry. Ive got one of these tanks running at work and the light output doesnt seem too much at all, waterchanges are done on it from topping up evaporation once a week. As said above, trying dosing liquid CO2 directly onto the algae. Most liquid CO2's active ingredient is an algaecide and should kill it off fairly quickly, with no harm to plants or fish of course

Sent from my SM-G928F using Tapatalk


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## Kezzab (12 Mar 2016)

Thanks for the comments.

The water change thing is interesting - apparently conflicting advice. General wisdom says big weekly water change if dosing EI and I noted George Farmer saying he does 2x75% on this same tank,who am I to argue! Yet you don't, in fact it sounds like you only top off evaporation, and would appear to have no issues. Go figure.

Ammonia/dirty tank seems most frequently suggested as associated with Staghorn - hence frequent big water changes. Yet 'unstable' systems are also claimed to cause it. Again go figure.

I'm steering clear of liquid CO2, it severely affected the moss last time i tried it.

So this what i'm trying:

Baking paper over the light to reduce intensity.
Cover back of tank to reduce ambient light from the window
Drop co2 to 2hrs before lights on, off 1 hour before lights off.
Maintain water changes for the time being at 2x75%
Continue EI at standard dose.

We'll see what happens.


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