High Nitrate Advise Please

[NatashaWoo]

Hi i have a 125 corner tropical tank. It is cycled had it running 4 months now.
1 bristle nose
1 long fun albino bristle nose
5 harlequins
4 neon tetra
12 guppy (males)
3 dwarf gourami
I do 15% water changes every week 50% every 4 (ish)always gravel vac when doing water change. On 50% week i move everything to clean under plants and decs.
My nitrate levels are always high and i don't understand why. Any ideas?

 

[fluttermoth]

15% is not very much for a relatively heavily stocked tank like yours, so the first thing to try would be making your weekly water changes larger.
 
What are the levels in your tap water? Obviously, you won't be able to get your tank lower than that with water changes.

 

[NatashaWoo]

Just tested ph of tap water. Is about 10
Is mine over stocked do you think? I didn't think it was. My bristlenoses are only 2inch max in size. Only babies

 

[fluttermoth]

A few bigger water changes then, and a larger % weekly and you should be able to get it down

 

[NatashaWoo]

How much would you recommend?30% maybe

 

[Byron]

I concur with fluttermoth.  
 
A partial water change of 50-60% of the tank volume once per week is advisable (I do this on all my 8 tanks).  You also have some notorious waste producers, like the plecos (even though small), so a good vacuum of the substrate in the open areas is advisable during each water change.
 
You don't mention live plants (I am assuming since you move "plants" to clean under them they are artificial), but these can help reduce nitrate too.  Even if just some floating plants.  Floaters are fast growers, which means they use more nutrients including ammonia/ammonium (which in itself means less nitrite and thus lower nitrate) and nitrate.

 

[NatashaWoo]

Cool thank you. I want to get some floating plants but unsure which to get

 

[cowgirluntamed]

I suggest water lettuce. I guess you could say I've done an unintentional experiment....my 20 gallon tank hasnt had a water change or even any water added in 6 weeks(don't hate me!! Lol.) I had done a water change prior to adding the water lettuce. The surface is like maybe a quarter full with water lettuce and one bigger water sprite cornuta(I think that's how you spell it?). I'm going to do a water change today, rather large(75%) mostly because I haven't done it in a while. I was expecting high nitrates...but when I tested this tank, and I did it twice to be sure...i basically had zero nitrates!! Ammonia and nitrite both zero too. This tank used to run around 20 to 30 in a month if I didn't do a water change. So...i highly think that the water lettuce is amazing!! (And I tested a couple of other tanks and I did read nitrates in those so the test kit wasn't bad.)

 

[NatashaWoo]

I'm glad to hear that. I've just bought some water lettuce. Fingers crossed it helps

 

[Byron]

Water lettuce is fine.  Water Sprite (Ceratopteris cornuta, the true floating species) if you can find it is ideal, and very beautiful.  Frogbit is another floater, if you get the true tropical species; there is a temperate water species often sold but it does not do as well in tropical tanks (I have it).
 
Floating plants are often termed "ammonia sinks" because they take up so much, which is why they are so useful in all sorts of situations including new tanks.

 

[AbbeysDad]

Yes, you either need plants or chemical filtration in addition to routine partial water changes...here's why:
Lets say your bio-load isn't too great and you don't overfeed, your gravel is clean and you service your filter regularly. And for discussion, lets say your tank generates 20ppm of nitrates per week and your source water is nitrate free, You do a 50% water change and your nitrates are down to 10ppm. By next week, your nitrates are at 30ppm...you do your 50% water change and your down to 15ppm...and the next week you're at 35ppm - it just keeps going up unless you do more frequent or larger water changes.
Culturing anaerobic bacteria to process nitrates into nitrogen gas is difficult if not impossible in a FW tank....jus typically too much O2. So we can use plants that will process ammonia or nitrates to keep nitrates lower. There are also several commercial resin pouch products that filter nitrates out of the water. API's Nitra-Zorb comes to mine and it can be recharged many times with ordinary salt water.
Floating plants may be your best choice. In addition to those mentioned, Anacharis is also a good choice and there are some good deals on Ebay.

 

[StevenF]

Any plant (including, if it grows well,  will consume all forms of nitrogen. including urea.  if it has sufficient phosphate, potassium, and micro nutrients available you can see zero ammonia, nitrite, and nitrate.  However note that if you frequently have very low nitrogen levels ( 0,0,0) you could develop high phosphate levels in the aquarium which could trigger an algae bloom. So for a planted tank about 10ppm in my opinion is about ideal.  
 
You didn't say what your nitrate levels are.  But if your tap water has 10ppm, more water cycles will not help.  Your nitrate levels will at a minimum be 10ppm.  if your aquarium is at 10ppm it is OK since it is 50% less than the recommended limit of 20ppm.  If it is more than  in your tap water you need to cycle water more frequently.  30% to 50% per week is what many people do.  To get it even lower you would have to reduce the nitrate level in your tap water before putting it in the tank or use plants and fertilizer.

 

[NatashaWoo]

Thank you all for advise. I always do my weekly water changes bit will start doing bigger ones. I'm waiting for my water lettuce to arrive. Hopefully this will help the levels of nitrates