GSA and some brown algae on HC

[Nos]

Hi everyone I have a problem with algae.
The tank is 400l but there are about 350l of water. It's been running for 6 months now. I had all sorts of algae about 3 months ago but that was sorted out with Easycarbo and pressurized CO2.

Originally tank had 2x54w T5HO tubes. About 6 weeks ago I've installed additional 2x54w T5HO tubes. Since the new lights were installed the plant growth increased and they are almost constantly pearling. But this also introduced Green spot algae which I never had before. I would not worry if it was only on the glass but it is attacking my plants. So to combat it I've reduced light period from 10 to 8 hours, this did not help. The second thing was to check my PO4 levels. It was 0.25ppm. I started adding PO4 every other day and keep at 2ppm but I still have GSA.
What should I do next?
Should I break my photo period?
Or should I only run all 4 lights for 4 hours a day and the rest 4 hours run only 2?

Also my HC looks like had not only GSA but also some kind brown algae (see image). Can anyone identify it and provide some info how to get rid of it?

My tank stats:
GH 12
KH 6
CO2 a lot if I turn more fish start gasping.
PO4 2
NO3 40
PH 6.6
WC once a week 30%

Thank you

 

[Gerryd]

Hi,

When you increased the light did you also increase the c02 and other ferts?

Light is what drives plant growth and thus nutrient requirement.

I would up your C02 a bit at a time, watch the fish, and that should clear it up.

I have the exact same symptoms when my c02 is not right.

Also as plant mass increases, this also needs corresponding increased c02/nutes.

Hope this helps.

P.S. Do you really need the extra bulb?

 

[Nos]

The fertz and CO2 were increased.
I added the light because I think 2x54w were not enough to reach the small plants like HC without the lights I never had HC pearl.

 

[Tom Barr]

Gerry was correct about the CO2, you will have more CO2 when you add more light, you also likely had limiting PO4, so those two together mean a lot more CO2 demand.

The HC looks very much like poor CO2.

You can use the easy carb + modify CO2.
Do the CO2 slowly when adjusting things.

HC will grow at fairly low light and may not pearl, higher light increases pearlign a fair amount.

But.....the demand for CO2 and nutrients also increase.

Regards,
Tom Barr

 

[Htomassini]

On my recently set up tank I am getting GSA on the rocks next to the gloss. My plants have doubled in size but I have not increased my ferts. I am doing ei with 3 days macros dry an and 3 days trace plus fe. I have noticed that on the second day after macros I do a no3 test and it is a 0 ppm. Should I do daily kno3?

Thanks.

 

[Gerryd]

Hi,

GSA is commonly low P04 or maybe c02...

Dosing daily will help rule out deficiencies. Don't be afraid to bump your EI dosing a bit, esp if getting good growth..As bio-mass INCREASES, c02, macros/micros also need to be increased same as if more light were introduced.

Is your test kit calibrated at all? If not, I would suspect any readings from it.. That being said, a healthy large tank will consume a lot of nutes daily.....

 

[Htomassini]

Ok. I started today by adding po. And I bumped up the co2. As of a couple of days ago I had 9ppm of o2 at 84f so the fish should be ok. I'm starting the co2 2 hrs before the lights go on. I also had an airstone in the sump running opposite of the lights. But I think I'll put it on it's own timer as to not degass the co2. During day ph drops to 6.5 and at morning it's up to 7.2. How do you calibrate a po tester if its thetesttube type?

Thanks