I second Red's advice, nitrate may be too low and CO2 is probably
insufficient. What macros do you dose? What are your KH, PH and NO3
levels? May be worth checking PO4 levels too. Chances are one of these
items is limiting plant growth therefore the extra flourish goes
towards feeding the algae. Not convinced on the light issue though, if
they are old tubes then they are putting out less light and probably
helping you avoid even worse problems. Changing the bulb before fixing
any nutrient imbalance may actually make things worse. Besides the
reduction in light output, I have never had algae problems due to
aging bulbs, just a slower growth rate.

Hope that helps
Giancarlo Podio

I second Red's advice, nitrate may be too low and CO2 is probably
insufficient. What macros do you dose? What are your KH, PH and NO3
levels? May be worth checking PO4 levels too. Chances are one of these
items is limiting plant growth therefore the extra flourish goes
towards feeding the algae. Not convinced on the light issue though, if
they are old tubes then they are putting out less light and probably
helping you avoid even worse problems. Changing the bulb before fixing
any nutrient imbalance may actually make things worse. Besides the
reduction in light output, I have never had algae problems due to
aging bulbs, just a slower growth rate.

Hope that helps
Giancarlo Podio

"nemo" wrote in message ...

Honestly, it seems odd to me that you can pull off 3.68WPG with DIY
CO2....

Ok, my first guess would be lights, how old, then I'd think maybe the DIY
CO2 is weakening, unless you are religous about swapping them out with new
batches....

What are your nitrAte readings? My 29 got over run with BBA, when I
refilled a CO2 tank, and ran out of PMDD, in just over 3 days, I had
things
covered... but it was a total crashing of 3 things, CO2 ran out, 55w pcf
lights were losing intensity, and PMDD ran out.... 3 days later, I was
crying.... heehee

My setup is new (~one month); lights, plants, substrate and all. The tank is
a converted all fish. I have not measured Nitrates or Phosphates in the
tank. I'm still spending the money on tank setup. I figured, however, that I
must be doing something right because the little brush/beard algae on the
fern and the hair grass is the only thing troubling me in the tank right
now. This is, of course, in addition to the fact that I can't get the CO2
levels to 10ppm because of the vigorous mixing/aeration I get from the
350GPH pouring over the tank 24/7.

I hope it is not just beginner's luck.

Well I will tell you none of the other nutrient matter till you deal
with the CO2 issue at this light intensity.
That is your first and upmost goal, 20-30ppm or so, that is what you
need during the entire lighting period.
CO2 will dog you like no other nutrient at high light.
Before you think anything, check and then double check it again.

Nutrients can be managed easily without test kits using water changes
with tap and a call to the local water company for NO3 and PO4 levels.
You can use large weekly water changes to remove any excesses and
dosing 2-3x a week will prevent anything from running out.
The weekly water change re sets the tank each week for any dosing
errors or lack of uptake, you can keep your NO3's in a better range
with this method than you can with even a Lamott test kit.

Good nutrient levels:

5-10ppm of NO3
..5-1.0ppm of PO4

Which is roughly the ratio of N:P in aquatic plant biomass(10N:1P).

Fe: don't bother, test does not give meanful results in terms of plant
growth, I typically will dose around 5mls per 20-25gal of tank water
3x a week at this light level. This is a better method than using a
test kit. You can change the dosage higher or lower after you get a
better feel for dosing.
K+ best done by estimation, 10-30ppm
CO2-20-30ppm

Gnerally most folks have issues with algae from a LACK of nuttrients
rather than excesses, high light and good CO2 drives nutrients down to
zero rather quickly. If you do get test kits, You can see this decline
yourself.

I'll dose this routine for 20-25 gallon tank:
KNO3: 1/4 teaspoon 2-3x a week
KH2PO4, about one rice grain's worth or a drop of Fleet enema 3x a
week
5mls of Flourish 3x a week
50-60% weekly water change
CO2 -20-30ppm

Repeat,
If the tap has a fair amount of PO4, 1ppm or higher, then you don't
need to add PO4 likely, same for NO3, but add K2SO4 for some extra K+
if you cut back on KNO3.

Regards,
Tom Barr