Removing Nitrates

[aluno]

I was wondering, ive been reading tropicall awuariums for dummies and in there is a list of tropical plants, one of which is one called an elodea or something (Anacharis i think is a better name for it), anyway in the discription it said it was good for removing nitrate from the water,

im just thinking, if i include a few of these will i be able to get away with fewer water changes, as the nitrates will be taken out by the plant,

this may be one of those, sounds too good to be true things but i just wanna know

also what other plants are good for leaching nitrates,

i know plants use the nitrogen CYCLE, so im not expecting a perfect solution im just looking for the clause
thanks

 

[xxBarneyxx]

Yes plants will help remove nitrate from the water. Floating plants and ones that take their nutrients from the water coloumn will do it better then ones that are primarily root feeders.

There is nothing better then regular water changes IMO though. For example in my planted tank I have no detectable nitrate at all. I still do weekly 10% water changes though. This mainly makes sure the buffering capacity of the water is kept up (stopping PH swings which would kill the fish) but it also helps remove waste particals from the tank.

Get a python water change system (or make one yourself for about £15-20) and a 10g water change can be done in about 5-10 minutes without having to use any buckets

 

[shroob]

Recently there have been alot of threads about reducing the amount of water changes or similar, theoretically it can be done. However I always view it as why take short cuts? If you're going to have fish, do it right. Its like having a dog, and then taking it for walks on a treadmill.

Sorry if that came across as harsh, I don't mean it to be, I'm just trying to say I believe water changes to be a fact of fishkeeping (Sure there are some tanks that may not require them, but I just believe water changes to be one of the components of having fish).

 

[TribeOfShroom]

Yes plants will help remove nitrate from the water. Floating plants and ones that take their nutrients from the water coloumn will do it better then ones that are primarily root feeders.

There is nothing better then regular water changes IMO though. For example in my planted tank I have no detectable nitrate at all. I still do weekly 10% water changes though. This mainly makes sure the buffering capacity of the water is kept up (stopping PH swings which would kill the fish) but it also helps remove waste particals from the tank.

Get a python water change system (or make one yourself for about £15-20) and a 10g water change can be done in about 5-10 minutes without having to use any buckets

Obviously water clarity is high on anyone's list, but I was just wondering. Wouldn't some of that waste material in your water be beneficial to your plants? Or do prefer feeding them liquid feed?

I just asked because I know I try and filter out most of the crud in the water, but (apart from when I do a gravel vac) I usually leave the crud on the bottom where it is so my plants have something to feed off.

 

[xxBarneyxx]

The plants get dosed daily with different mixes of ferts but I dont gravel vac (there are almost always eggs, shrimp or fry in the way and I only have about 3" of substrate visable so dosnt work for me).

That said though I do get debris build up among the stems of the plants and bits of plants (after I trim them up) which I prefer to not have floating around.

I'm pretty sure if I just left it as it is and only topped up with fresh water once a week it would most likely be fine for a long time (I have pretty hard water so would take a long time for it to lose its buffering capacity) but there is more in the water then you can see and test for (with the typical test kits most fishkeepers have) so I still do water changes.

If you have a really big (100g+) heavily planted tank with auto top off then you could most likely get away with not doing any water changes. In smaller tanks though there just isn't enough water volume to dilute anything that might build up in the water unless you do regular partial changes.

 

[TribeOfShroom]

If you have a really big (100g+) heavily planted tank with auto top off then you could most likely get away with not doing any water changes. In smaller tanks though there just isn't enough water volume to dilute anything that might build up in the water unless you do regular partial changes.

Hmm good point.

 

[Dave Spencer]

Why do you wish to remove nitrates? Are they too high?

In my opinion, using plants to reduce nitrates is a waste of time. I run heavily planted, high light tanks that have very rapid plant growth that take up something in the vicinity of 5ppm NO3 per day. Using Egeria densa (I think that is the plant you are referring to) in limited numbers in a low light tank will have a negligible effect.

The only purpose of plants in a tank is if you want them there.

By the way, plants don`t use the nitrogen cycle as they don`t take up NO2 as a nitrogen source.

Dave.

 

[ibbledibble]

By the way, plants don`t use the nitrogen cycle as they don`t take up NO2 as a nitrogen source.

Dave.

Uhh yes they do.
in preference to NO3 actually.

ecology of the planted aquarium by diana walstad

 

[Dave Spencer]

The article you linked to outlines plants` preference of NH4 as a source of N over NO3, so isn`t particularly relevant to my line you quoted.

Ecology of the Planted Aquarium, p.22 Nitrite Uptake by Plants:

"Do aquatic plants remove the toxin nitrite in preference to the non-toxic nitrate? No definitive answer to this question in the scientific literature is currently available."

She does, however, go on to mention her observations that Spirodela oligorrhiza does take up nitrite in preference to nitrate.

Nitrogen Cycling in Planted Aquariums, Tom Barr (June 2005):

"While there is some scant evidence that plants will use a small amount of NO2-, it is generally a toxic anion that plays an insignificant role in our tanks after a period of new tank cycling (planted tanks). Try adding NO2- and see if the plants remove any significant amount. Try many species. The concentration will sit there unless you have bacteria to convert it to NO3-, in which case the NO3- will be removed (by plants)."


Dave.

 

[TribeOfShroom]

Sorry if this is a really stupid Q, but don't aquatic plants take the same nutrients as terrestrial counter parts?

 

[Dave Spencer]

Yep, pretty much...as does algae.

Dave.