OK, so I probably have too much light...

I am just back from a week in CA and after the ritual PWC of the morning I noticed that I have some green spots on my glass and a few of my Crypt and Pennywort leaves... My Alternanthera Reineckii has always seemed to gather a bit of green algae on it's older leaves, as it grows very slow, but I have not had any real problems with it spreading, etc. Is this the same stuff?







Is this a high-light problem? Anyway of fixing it without taking away light, or is that the only real issue here? It is only on a few leaves. I have already scrubbed it off the glass.

Stats:

72g Freshwater Bowfront
Pressurized CO2 w/Regulator and Solenoid
SMS122 pH Monitor
Reactor 1000
Inline 300w Heater
2x Rena XP3 Canisters
324w HO T-5 Lighting (10k bulbs)

EI Dosing (KNO3, K2SO4 and Flourish Comprehensive)
Tap pH: ~8.0
pH After CO2 Injection: ~6.8
kH ~120ppm
gH ~200ppm
Temp: ~79F
Lights: 10 hours full blast (324watts) + 2 hours dusk/dawn (108watts)

I don't test much any more, so I am not sure on the other things, but they should be pretty close to the EI marks. Plants pearl from early afternoon until the lights go out every day.

TIA

 

Well, I thought by using T5's that I was supposed to mulitply the standard WPG rule by something like 1.7... Which would give me >7.6 WPG.

I have never had to dose Phosphates, as typical feeding seemed to keep my level about right... The tank is realitively clean of mulm, etc... Hmmmm.... I will run some test tomorrow to see where things are at.

What causes this kind of algae?

 

Peter, The tank is very healthy overall. I have not dosed Phosphate as my test always shows more than 1 (whatever the measurement is) in the tank, which I assume is from feeding. I do have some Mono Potasium Phospahte (a couple lbs) but I was worried that adding any would be a bad thing. How much of this stuff should I be adding?

The tank before a very large trimming and the removal of a bunch of (too) fast growers:


The tank just after (yesterday):


Everything is growing at a nice pace, even the slow growers.

 

Interesting reiverix. I will try adding some KH2PO4 today after I run some test. I have not had any spot algae problems before, and hesitate calling what I have now a "problem" really. Just a few leaves on a couple plants and a little bit on the glass. I just don't want it to become a problem!

From what I have gathered, NO3 is best around or under 10ppm, but everything will remain stable within a large variance, as long as you avoid extreme amounts (>100ppm) and bottoming out. I understand K to be the same, or easier... Not sure about PO4 though. What kind of variance can I run in the tank without much risk?

 

Sure enough, PO4 was between 0 and .25ppm. That is the lowest I have ever seen it. Just added a bit with today's NO3 and K dosing... A pinch or so (~ 1/8 tsp).

Are there any good reference sites / literature on controling this kind of algae? If I balance out my PO4 between 1-3ppm, do I still need to worry about the lighting cycle? Thanks VaughnH, Peter and reiverix.

 

I also dose K2SO4 for additional K... Do the 50% PWC every saturday and also dose KNO3 and Flourish Comprehensive. Inject CO2 to around 30-35ppm using an automated system. Until now my PO4 was naturally high (>1ppm), so I avoided dosing. Looks like that is starting to change, so I will add KH2PO4 to my routine.

Thanks for the help.