How many plants to lower nitrate level?

[Stryker]

Hi there,

I have a 120L tropical tank, note for fish stock see my sig. I currently have two amazon sword plants and 2 other plants I cant identify. They have stems coming up from the root ball and each stem is covered top to bottom in little bristle type leaves (look more like soft green spines than anything else).

Anyways. I got thinking, if there are enough plants in a tank then the nitrate levels will take longer to build? anyone have any hands-on data on this?

 

[Tempestuousfury]

Plants don't remove very much nitrate unless kept in large groups. They primarily take in ammonium and ammonia. This is good to stop nitrates in its incipient stage, but only water changes can lower your nitrates right now.

Don't get me wrong, though. Having plants (quite a few) does mean that you have to clean the tank less.

For research, read "Ecology of a Planted Aquarium". That's where I got the info from.

Good plants would be java ferns because tehy don't require as much care and they use their leaves to take in ammonia and nitrates (and they have pretty big leaves). their roots are pretty much only good for anchoring.

Sorry, the name of that book was wrong...

 

[Bol]

From what I've experienced and read, I don't think plants will significantly reduce your nitrates unless you get into a higher-than-standard light situation. Could be wrong.

The only data I can offer is this: I've got a (roughly) 180L tank, that's pretty heavily stocked in both fish and plants. At standard lighting (which was 30W), normal behavior was for nitrates to be around 10ppm after a water change, and it would rise to 20ppm in about a week.

Then, I increased the light to about 1.8 watts per gallon, and found that it took closer to 10-14 days for the nitrates to rise to 20ppm.

 

[mrV]

I got thinking, if there are enough plants in a tank then the nitrate levels will take longer to build?

If you have lot of fishes, then they also produce lot of waste. Also doing water changes regularly and change water enough, it reduces not only nitrates but also other harmful compounds too.

But yes, there are some plants that almost "eat" fertilizers, e.g.:

- Vallisneria sp.
- Lemna minor
- Ceratopteris cornuta
- Ceratopteris thalictroides
- Eichhornia crassipes
- Limnobium laevigatum

Both Ceratopteris need first space and second light. E. crassipes needs lot of lights. Vallisneria sp. grows better liitle bit harder water than very soft.

So, how much light you have? What are your water values?

 

[Stryker]

Thanks for your help peeps. Yep have been reading up of late. My tap water has a PH of 8.0 so I'm also interested in what I've read re plants bringing down the PH a little.

I've got 40 watts of light, plant friendly flourecent. Tank is 19" high, 120L.

I appreciate nothing will do away with good tank keeping.... I was just interested in how plants may slow down nitrate build up and also make the tank more stable, ie adding 6 zebras to a planted 120L tank may not have the same "hit" to the system as adding 6 zebras to a non planted 120L tank.

I like real plants, I just also want to know my efforts in keeping real plants will have some other benefits too

The reading material out there is good, but you cant put a value to the comments like those above from experienced fish keepers, cheers.

 

[Tempestuousfury]

I'm glad to know you're not just being lazy.

A planted tank helps create balance in the tank, so if you want to reduce stress in the tanks, plants'd really help.

 

[Olive]

I got thinking, if there are enough plants in a tank then the nitrate levels will take longer to build?

If you have lot of fishes, then they also produce lot of waste. Also doing water changes regularly and change water enough, it reduces not only nitrates but also other harmful compounds too.

But yes, there are some plants that almost "eat" fertilizers, e.g.:

- Vallisneria sp.
- Lemna minor
- Ceratopteris cornuta
- Ceratopteris thalictroides
- Eichhornia crassipes
- Limnobium laevigatum

Both Ceratopteris need first space and second light. E. crassipes needs lot of lights. Vallisneria sp. grows better liitle bit harder water than very soft.

So, how much light you have? What are your water values?

wow....plants to lower ph.............never thought of that..........lemme know if you find any, okay?

 

[Bol]

so I'm also interested in what I've read re plants bringing down the PH a little.

Never heard of this, myself. Injecting CO2 (which many people do for their plants) will bring down your pH, of course.

 

[Stryker]

I could swear I'd read about plants bringing down the PH in one of the recommended reading sites on this forum.

tempestuousfury, thanks that sounds good enough reason to persist with them. They do look pretty too, apart from my amazon sword has some brown spots on the leaves, I fear its the begining of the end. Guess I'll have to invest in some plant pellets.

 

[mrV]

I got thinking, if there are enough plants in a tank then the nitrate levels will take longer to build?

If you have lot of fishes, then they also produce lot of waste. Also doing water changes regularly and change water enough, it reduces not only nitrates but also other harmful compounds too.

But yes, there are some plants that almost "eat" fertilizers, e.g.:

- Vallisneria sp.
- Lemna minor
- Ceratopteris cornuta
- Ceratopteris thalictroides
- Eichhornia crassipes
- Limnobium laevigatum

Both Ceratopteris need first space and second light. E. crassipes needs lot of lights. Vallisneria sp. grows better liitle bit harder water than very soft.

So, how much light you have? What are your water values?

wow....plants to lower ph.............never thought of that..........lemme know if you find any, okay?

Hmm... Im totally confused - plants lower pH??? What has it to do with my reply?

 

[Henry_VCG_]

If you have lot of fishes, then they also produce lot of waste. Also doing water changes regularly and change water enough, it reduces not only nitrates but also other harmful compounds too.

But yes, there are some plants that almost "eat" fertilizers, e.g.:

- Vallisneria sp.
- Lemna minor
- Ceratopteris cornuta
- Ceratopteris thalictroides
- Eichhornia crassipes
- Limnobium laevigatum

Both Ceratopteris need first space and second light. E. crassipes needs lot of lights. Vallisneria sp. grows better liitle bit harder water than very soft.

So, how much light you have? What are your water values?

You had to use the scientific names didn't you

 

[Bol]

Common names:

Lemna minor - duckweed
Ceratopteris cornuta - Indian fern
Ceratopteris thalictroides - watersprite
Eichhornia crassipes - water hyacinth
Limnobium laevigatum - frogbit?

 

[modernhamlet]

I have minimal light in my 29g tank, but planted heavily with low light plants and can say, with some certainty that plants do reduce nitrates considerably. I test nitrated ever couple of days and my current (heavy) level of planting seems to be maintaining the nitrate level at around 15-20 ppm.

I utilize the following plants:
Hygrophila polysperma (dwarf hygrophila)
Java Fern
Java Moss
Thai onion
Wisteria
Cryptocoryne wendtii

While I don't know the exact chemistry involved, my plants have clearly stablized the tank considerably.

 

[mrV]

You had to use the scientific names didn't you

Yes, because I don't know what they are in english I could have certainly used also finnish names, but I think, you could be very confused after that. Also, when you search more information, then you definately find it easier when using scientific name.