Lower Nitrates

[Proxo]

Can i lower nitrates by doing smaller water changes every day or is it better to do big water changes every so often?
I'd say my nitrate is hitting about 80ppm (hard to tell between the reds, but i'd say it's getting close)
my tap water is 20ppm..

There's no live plants in the tank yet but i'm planning on it to help with the nitrate lol.

Muchos Gracias

 

[KittyKat]

Smaller regular water changes will not change the water chemistry as much in one go as a single large one will, so the first would be my preference. You will see more of a difference in nitrate readings before and after a large water change, of course.

 

[Joshwainwright]

Personally, I would prefer to do larger water changes less often as it seems less of a chore. Also, I don't think small and frequently is much different to large and infrequently.

 

[KittyKat]

Also, I don't think small and frequently is much different to large and infrequently.

For example, my aquarium water is pH 6.0 and my tap water is pH 8.0. Just think about the havoc if I replaced 50% of the water with something that has completely different chemistry.. if I had been keeping any delicate fish, they would be dead by now.

On the other hand, if I replace only a small amount of water, the pH would not rise by as much because of the new water so the fish would not be affected as much.

pH is only one example.. I know that my water hardness differs a lot too and the aquarium water has lower nitrates. There are also countless other factors which could be important that I can't measure.

 

[fishlove75]

It really depends on the chemistry of your tap water. If your tap water is at 20ppm I would be inclined to do smaller changes more frequently. However, I remember reading something a while back that you want to do a water change once the nitrates hit 15-20ppm above your tap water (providing all other parameters are good). I could be wrong on that, just something I read a few years ago. But truthfully if your nitrates are so high coming out of the tap have you considered a RO unit. I know they can be pricey but mite worth it espically if you are keeping expensive and or delicate fish. 20 right out of the tap just seems really high to me. I think I would get an ro unit just for my own drinking water. But that is just me.

 

[Joshwainwright]

Also, I don't think small and frequently is much different to large and infrequently.

For example, my aquarium water is pH 6.0 and my tap water is pH 8.0. Just think about the havoc if I replaced 50% of the water with something that has completely different chemistry.. if I had been keeping any delicate fish, they would be dead by now.

On the other hand, if I replace only a small amount of water, the pH would not rise by as much because of the new water so the fish would not be affected as much.

pH is only one example.. I know that my water hardness differs a lot too and the aquarium water has lower nitrates. There are also countless other factors which could be important that I can't measure.

When you think about it that way then I guess it is better to do smaller, less frequent water changes. Sorry for not realising that.

 

[Rynofasho]

If your fish can handle large water changes and there are not a lot of chemistry differences (aside from ammonia, nitrite, and nitrates) from the tap to the tank, you can do larger changes. Also bear in mind that a quick accumulation in nitrates points to a dirty substrate / overfeeding, so be sure you are REALLY vacuuming well. If you have gravel, try lowering the overall level a little bit so it is easier to vacuum to the bottom of the tanks.

 

[Geoff-]

Smaller changes won't change the chemistry much and they also won't change the nitrate level much.

If you do a 50% change between pH 6 tank water and pH 8 tap water you will jump to pH 7. If your fish are very delicate you may have issues but most tropicals should cope. My tank water reaches 6.5 with driftwood in it and my tap water is 8. If I was keeping discus I might be worried but tetras and BN catfish dont' seem too fussed by majority changes.

 

[Rynofasho]

If you do a 50% change between pH 6 tank water and pH 8 tap water you will jump to pH 7. If your fish are very delicate you may have issues but most tropicals should cope. My tank water reaches 6.5 with driftwood in it and my tap water is 8. If I was keeping discus I might be worried but tetras and BN catfish dont' seem too fussed by majority changes.

That is not true. Mixing 50% ph 6 water and 50% ph 8 water will not give you a ph of 7 in your tank. There are far too many variables for it to be that simple. The main reason it is inaccurate is that you are completely ignoring kh or your water's buffering ability to stabilize ph.

 

[KittyKat]

If you do a 50% change between pH 6 tank water and pH 8 tap water you will jump to pH 7. If your fish are very delicate you may have issues but most tropicals should cope. My tank water reaches 6.5 with driftwood in it and my tap water is 8. If I was keeping discus I might be worried but tetras and BN catfish dont' seem too fussed by majority changes.

That is not true. Mixing 50% ph 6 water and 50% ph 8 water will not give you a ph of 7 in your tank. There are far too many variables for it to be that simple. The main reason it is inaccurate is that you are completely ignoring kh or your water's buffering ability to stabilize ph.

+1, a difference in pH of that much can easily cause a crash.