# My BGA & Fuzz Algae problem, and my plan of attack: your comments appreciated.



## Osteomata (Jan 11, 2005)

Hi, some help appreciated. My assessment of my problem and plan of attack at the bottom:

Tank: 15G High, 40 Watts PC 6500K, Flourite and Eco-Complete mixture substrate, Zoomed 501 Canister filter, DIY CO2 injected into filter intake, tap water, Flourish Ferts (Flourish, Nitro, Potas, Phos, Iron) roughly based upon instruction on bottles. 

Parameters:
pH: 6.5 (measured 3 hours after lights on)
Ammonia 0
Nitrite 0
Nitrate 0-5, tough to tell with this kit
GH 7
KH ? my test kit seems to be bad, did not even get much of the start color. 
CO2 estimate seems off the chart if I assume kH is higher than gH. Fish are fine though....

Algae: Primarily BGA all over the plants, hardscape, and substrate. Fuzz algae at the top of the tank(cotton balls around heads of stem plants)

Recent changes: Until 20 days ago the tank was non-CO2 and no ferts, but I was having trouble with lots of fuzz and hair algae. I did not have any test kits here at the office, so I assumed excess phosphates from high bio-load. So 20 days ago I rigged up CO2, reduced bio-load to about 1.25 inches/gallon, and set up a conservative fert regime based upon the Seachem bottle instructions. I left for a couple weeks on a business trip, left the ferts pre-mixed for a two week period, which an office mate dutifully added each week. 

Plant growth: I am still seeing good plant growth, its just covered in BGA and fuzz. 

My assessment: I have a nutrient deficiency, not excess. The high CO2 levels are allowing the plants to soak up the limited ferts, leaving very little nitrates but reasonable phosphates, and no iron (probably little left of other traces too). Additionally, premixing all the ferts together and leaving them in a bottle of water resulted in some chemical interaction and reduction in potancy. The algae is taking advantage of this imbalance.

My plan: 
1) Mechanically remove as much as I can, cut the tops of the stem plants to remove the fuzz algae today.
2) 30% Water change and clean the tank today.
3) Increase ferts, particularly Nitrate and Potasium and traces, but keep phosphates about the same.
4) Frequent testing throughout the week to monitor Nitrate and Phosphate levels.
5) If by Friday I don't see some reduction in Algae growth, 3 day blackout. 

Your thoughts on my assessment and plan?


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## Bert H (Mar 2, 2004)

Osteo, I am NOT an algae expert, by any means, but a couple of things...

It has always been my understanding that high bio-load usually results in high nitrate, not necessarily phosphate. 

What I would do is to manually clean and remove as much algae as you can. Give the gravel a good vaccumming whereever you uproot/re-plant. Do a large water change - 60% or so. Then add back nitrates, and phophates to around 10ppm and 2ppm, respectively. You can calculate the rough amounts from the fertilator. I would also add a little potassium. Living in South Florida, there's no way you're going to have too soft a water, so you should be ok along those lines. Dose your micros the next day. Mid-week, I would repeat your NO3/PO4 dose followed by micros again.

Regarding the CO2, take an aliquot of your tank water and let it sit out 24 hours to equilibrate with room air. Measure the pH. Then aim for a pH in your tank of 1.0 pH unit below your equilibrated sample. 

BGA can be hard to deal with, but from what I recall, low nitrates are involved.

My suggestion is to do larger water changes while you're battling the algae, rather than smaller ones, especially if you're going the CO2 route. And don't forget to clean your filter as well.

Good luck!


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## Osteomata (Jan 11, 2005)

Thanks Bert, I think we are talking along the same lines, except for your recommendation of a higher % water change, your specific dosing recommendations, and the equalibrium state pH testing. I'll modify my plan accordingly.


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## Zapins (Jul 28, 2004)

Hehe, thats interesting to know... I was doing a test with very low if not 0 ppm nitrates and high phosphates and some small spots of BGA started to appear. 

Pretty cool to know you can trigger it on command!!!


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## Laith (Sep 4, 2004)

Your assessment is pretty much spot on: you have a deficiency and low Nitrates are a BGA trigger.

Bert's advice is good. I like to keep Nitrates at around 20mg/l so I *know* that I don't risk bottoming out.

Hobby test kits are notoriously off and need to be "calibrated" (tested against a known concentration) to ensure that the results they're giving you are more or less correct.

And keep in mind that the recommended dosing on the Seachem bottles are not really for high light (>2wpg) tanks with CO2 injection. The Seachem base recommended dosing for Nitrogen only adds about 1mg/l twice a week or 2mg/l a week. Higher light tanks with CO2 (and *well* planted) are usually dosed 2, 3 or even 4mg/l per day.

Do a search on the Estimative Index. It's a good simple dosing method that will keep you from bottoming out on your nutrients.


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