# Nitrogen, Nitrate and Algae



## yznj99 (Nov 1, 2004)

I think some commerical nitrogen fertilizers have mainly nitrate but also guanidine? or stuff like that. Some plants can not use nitrate well, that's the reason they add in some ammonia based nitrogen source (not free ammonia and not toxic)

Both plants and algae are the same, they need nitrogen and other nutrients to grow, they can take in nitrate, ammonia or nitrogen from other sources, some algae like BGA can even use nitrogen gas in the air as a nitrogen source. 

Adding nutrients to the aquarium will help both plant and algae grow. However, if plants are fast growing, they grab any resource that's available like ammonia. Mr Barr thinks algae spores use ammonia level as a signal for gemination. If ammonia levels are lowered by fast growing plants, algae growth is slowed and your plants will outcompete algae.

Of course in the real world there is a subtle balance between nutrients, CO2, light, fish load, and I think most importantly, plant biomass and algae biomass. People have been using EI method to avoid tedious and expensive measurement of nutrient levels and such. If your tank is already algae infested, you may need drastic measures like a blackout, or even a restart.


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## plantbrain (Dec 15, 2003)

yznj99 said:


> Some plants can not use nitrate well, that's the reason they add in some ammonia based nitrogen source (not free ammonia and not toxic)
> 
> 
> > All plants can use NO3.
> ...


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## Hoppy (Dec 24, 2005)

If you have BBA you can be reasonably sure you don't have enough CO2 in the water. Don't just test pH and KH and get the ppm of CO2 from the tables. That might possibly be an accurate measure of CO2, but much more likely it is overestimating the CO2. Use those measurements as a startiing point only. From there, try raising the bubble rate on the CO2 a little at a time, watching the fish for any sign of distress, watching the plants and the algae to see if the plants are pearling good and the algae is not starting again after you remove it. Keep increasing the CO2 until either the algae leaves you alone or the fish are unhappy - in which case back off a bit on CO2. Now, look at the bubble rate and the KH/pH derived ppm of CO2 and use those numbers as your goal.


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## Digsy (Mar 4, 2006)

Yzn, thanks for the clarification on the contents of Nitrogen ferts. Now if I can figure out if nitrates are really my problem. 

Hoppy, as far as the CO2 goes, unfortunately, I'm using the Hagen plant system for CO2 so, that prevents me from regulating it in any way. Would you go pressurized for a 12 gallon? I kept hoping that the plant system CO2 would be enough but, apparently it isn't. 

So, nitrates are not as big of a problem if BBA is present? I keep getting them confused. My 58g with all the BGA looks like a huge mess and I can't remember which advice to use for which algae. There's almost too much knowledge on this site. It can be a little overwhelming sometimes. I recently tore out a bunch of plants from the 58g because theey were so infested with BBA and now there's an infestation of BGA...should I put more stem plants in to temporarily suck up the nutrients?


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## Hoppy (Dec 24, 2005)

With a 12 gallon tank you can probably substitute Flourish Excel for CO2, and it wont cost a months pay to do so. That's what I would try. If your tank has more than about 36 watts of flourescent light and with good reflectors I think you really need either CO2 or Excel or both to avoid algae problems. The need for CO2 is really determined by how much light you are providing, and for smallish tanks, up to 2.5 or 3 watts per gallon is, I believe, doable without CO2. For larger tanks, the watts per gallon where CO2 is very desirable is lower - like 2 to 2.5 watts per gallon. Those numbers are really crude estimates, and I'm sure others will say they should be something else.


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## plantbrain (Dec 15, 2003)

Rather than chasing algae and the issues with them, focus on providing good plant health.

DIY CO2 users have more issues with BBA than all others combined.
There is a reason for that.

That will be the hardest thing for you to deal with.
EI can take care of the nutrients for you, but the CO2 is up to you.
You added more CO2 and then got BGA, this is due to increased plant growth removing the NO3 faster, likely bottoming it out.

So you are chasing one issue to the next.

Rather than doing that, you can try EI and this will rule out too much NO3, or too little(and all the rest of the nutrients).

Then it's all about CO2.
CO2 accounts for about 90-95% all algae issues and the rest is due to a lack of some nutrient in general or an excess of NH4(which we do not add except in the case of small amounts via a balanced fish load).

Regards, 
Tom Barr


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## Digsy (Mar 4, 2006)

Hoppy, I'm going to give supplementing the existing (albeit small) amount of CO2 with Flourish Excel. See if that does the trick. 

Thank you for the excellent advice, Tom! That makes up my mind about spending my effort on the CO2. It seems as though ferts are not the issue.


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## plantbrain (Dec 15, 2003)

When I used DIY for a decade I ended up using those internal DIY reactors I designed, these work better than anything made for DIY.

They cost 2$ and the cost of a small Rio 180 powerhead.
Takes about 15min to make and are small.

These are the best thing for DIY users peroid.
There's a diagram on my site on the free side and instructions etc.
PT is welcome to repost the instructions/pics etc here also.


Regards, 
Tom Barr


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## RoseHawke (Mar 10, 2004)

My little 10 gallon was starting to get a bit of BBA. Now, this is supposed to be a low-tech/low-light/low-maintenance tank, so ferts, water changes, CO2, etc., is not an option. Flourish Excel I don't mind though. Started dosing a bit more than recommended, 1.5 ml daily for this tank. The BBA went away within a week, ten days.

So did the anacharis . Some few plants are apparently a bit sensitive to it.

Oh, well, wasn't particularly fond of it anyway .


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## Digsy (Mar 4, 2006)

RoseHawke, I was wondering just how accurate I needed to be on the Excel. I'm now dosing daily but haven't bought an eye dropper for it yet so, I'm just guessing on about 1/4 of a capful for my 12g. I'm hoping that does the trick! Did you have any problem with fish deaths? I guess I'll find out which of my plants are sensitive to it!


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## plantbrain (Dec 15, 2003)

Excel will do the trick but you still have not figured out how to use the CO2 gas which was the original issue that lead to BBA.

Excel is somewhat easier to dose and also supplies CO2.
So that will help the plants in a similar way, Excel does not have to be that accurate in the dosing, just consistently add close to the suggested to 2x the rec amounts.

Regards, 
Tom Barr


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## Steph_D (Apr 20, 2006)

plantbrain said:


> When I used DIY for a decade I ended up using those internal DIY reactors I designed, these work better than anything made for DIY.
> 
> They cost 2$ and the cost of a small Rio 180 powerhead.
> Takes about 15min to make and are small.
> ...


Tom, I have searched your site and can't find the "free side" anywhere. Maybe I'm tired and just overlooking it?? 

Thank you so much for helping us newbies! :thumbsup:


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## plantbrain (Dec 15, 2003)

Well, like any forum such as this site, you must register first.
Then look under DIY.

Regards, 
Tom Barr


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## Steph_D (Apr 20, 2006)

Thanks Tom. I finally found it, not long after I'd posted here. I'm still trying to wrap my tired mind around the set up, but I think I've figured it out. I'm hoping this will help my 55g.

Thanks again!


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## plantbrain (Dec 15, 2003)

It's not brain surgery, so do not sweat it, you can fix and redo the thing many times for peanuts.

Regards, 
Tom Barr


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