[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Blackout



Having suffered through a hair and staghorn algae infestation through much of 
it's 2 month existence, I finally plunged my heavily planted 75 gallon tank 
into total darkness for 5 days and the results are most encouraging. The vast 
majority of the plants used initially were collected from the wild, planted 
without any type of disinfection and were no doubt the source of the 
unbelievable algae jungle that developed under 220 watts of CF, tank CO2 
injection and heavy water column fertilization. The dKH is between 3 and 5, 
the GH between 5 and 8, and the pH fluctuates between 6.6 - 6.9 as I use no 
controller. The substrate is Flourite and Turface and the fish load was: 5 
Black Mollies, 5 ottos and 35 cardinal tetras. I have a LaMotte phosphate 
test kit but could never measure any phosphates. Gomberg's iron test always 
read under 50 ppb (that's billion). I toyed with the nitrates using the 
standard and latest PMDD ratio to kick them up as high as 10ppm according to 
an Aquarium Pham. nitrate test kit - but they'd always fall to zero by the 
next day. Plant and algae growth was spectacular.
After trying nutrient limiting strategies as per PMDD methodology - I finally 
gave up and after bleach treating all my other smaller tanks and containers I 
was faced with this remaining 75gal - my only relatively high tech tank. I 
thought I'd give this one the blackout treatment in a last ditch effort 
before using ionic copper or total bleaching - a task I have little appetite 
for. Besides, I need more time to grow enough algae free plant material to 
replant the darn thing with anyway.
I disconnected the CO2, removed most of the fish, pulled out as much algae as 
I could stomach, did a 90% water change and then wrapped the whole thing in 
furniture blankets for 5 days. Upon removing the blankets and turning on the 
lights I was astounded to find no, zero, zip live hair algae observable, only 
some faint brownish mush in the areas I remembered as being the most heavily 
infested. Before the blackout, there was not one leaf in that tank which 
didn't have at least some fuzz on it.The water was crystal clear and only the 
most careful of observation revealed scattered traces, gelatinous skeletons 
only perhaps, of the silvery gray, branching algae I believe is called 
staghorn - and which was still attached to the Flourite here and there. I've 
pulled out every piece of it I can find. BTW, the plants themselves made it 
through the blackout fine - they just elongated slightly and look a little 
pale. I only gave them 5 hours of light the first day.
I did another 90% water change, turned the CO2 back on and drastically 
trimmed the pearlgrass and hetra zosterfolia - the two species which had the 
heaviest hair algae infestation. I then introduced a total of 11 ottos and 1 
male FFF which had been quarantined for 48 hours to clear their little guts 
out. I checked the nitrates a day later. Zero. 
That was two days ago and I wonder what to do next. Do I kick up the nitrates 
up again a la PMDD to stimulate plant growth and suck up and limit the 
already unmeasurable phos and iron or does water column fertilization this 
soon (or perhaps in general) risk the revival and return of hair and other 
algae whose spoors might still be present? If I deprive the water column of 
nutrients could I possibly starve whatever algae might be present into 
extinction?
One thing I do know, if I hadn't introduced that hair algae in the first 
place - I wouldn't have to ask silly questions like this. Prof. Krombholtz is 
right - that stuff doesn't float through the air and it really doesn't take a 
lot of effort to avoid it once you're rid of it. Never again.

Bob Olesen
West Palm Beach