How to raise nitrate levels?

[Biglog]

I have a large blue-green algae bloom that I believe is caused by low nitrate as the are below 5ppm. I would consider my tank fully stocked and possibly over stocked so adding more fish probably isn’t really an option. I use all of the seachem fertilizers so should I just dose more than the recommend amount of the nitrogen one?

 

[Byron]

Cyanobacteria (which I assume is what you are referring to by the common name blue-green algae, correct me if it is something else) is not caused by nitrates being low. High nitrates are more likely to be associated with cyanobacteria because it is caused by high organics in the presence of light.

Second, no fish that I know of (suited to a home aquarium) will eat cyanobacteria.

The Seachem fertilizers are probably a significant factor here, along with the fish load. Removing organics and balancing the light is how you solve cyano. Adding plant fertilizers can counter your efforts; the two times I had cyano in one tank (never in the other 8) I stopped using the Flourish Comprehensive Supplement, the reason being to make the plants use the organic nutrients and deprive the cyano. This did help, and I reintroduced the FCS when the cyano was gone.

Nitrogen should never be added to a tank with fish, though I realize a high-tech planted tank needs it--maybe. But the fish do not.

 

[Biglog]

My plants are showing signs of nitrate deficiency and what I read about the Cyanobacteria is that it doesn’t need the nitrates like plants do so it takes advantage of all of the nutrients that the plants can’t.

 

[peterwoods]

To prevent starving your plants, however, if your planted tank consistently has too little nitrate, you should administer fertiliser on a regular basis. Starting out, we advise dosing Easy Green at a rate of 1 pump per 10 gallons of water as follows: In low light tanks, dose once per week.

 

[Essjay]

That sounds as though you are quoting from a fertiliser-selling website. Aquatic plants prefer ammonia to nitrate. Unless it's a high-tech tank with few fish, there will be enough ammonia for the plants without adding nitrate.



As a side note, quoting from other sites is not allowed unless you give a link to that site. Unless the other site acknowledged it's plagiarism which is against the forum rules.

 

[sharkweek178]

I have a large blue-green algae bloom that I believe is caused by low nitrate as the are below 5ppm. I would consider my tank fully stocked and possibly over stocked so adding more fish probably isn’t really an option. I use all of the seachem fertilizers so should I just dose more than the recommend amount of the nitrogen one?

You don't need to use all of the fertilizers. You just need to use one, the Comprehensive. And the dosing depends on your tank. Some people dose less than directed and that works for them. Some people need to dose more than directed.
The cyanobacteria or algae is caused by an imbalance. Your tank is getting either too much light or too many nutrients. The great thing about having plants is that they will always outcompete algae for nutrients. But if your tank has more nutrients than the plants need, then you'll get algae. So it sounds like you might need to dose less fertilizer, not more.
Some specifics could be helpful. Could you tell use how big your tank is and what you have in there as far as livestock and plants? Also, exactly what kind and how much fertilizer are you using? What kind of lighting to you have and how long do you keep them on?

 

[Byron]

I agree with both essjay and sharkweek above. Plants use ammonia/ammonium, not nitrate [this is basic, there are differences but there is no point in getting into this, it will not help]. Nitrate needs to be as low--as close to zero--as possible for fish. And as you indicate a good stocking, the ammonia/ammonium will be more than adequate for the nitrogen needs of plants. A photo of the entire tank would help us here though.

And a list of the plant additives. What you see as a deficiency could also be caused by the light, so data on this will help.

 

[Bpfoto]

Just manually clean it off the glass with a clean aquarium sponge and it will balance out eventually. If you have a good cleanup crew (Corys, SAE, Pleco, or Snails) they help keep everything in balance. Good luck.