The importance of water changes and relevance of Nitrate

[Rastapus]

Hey everyone,
Need for water changes and frequency of them is likely one of the most frequently asked questions. I decided to do a sticky on this somewhat misunderstood topic.
Firstly, yes, all aquariums require water change to dilute pollutants and replace needed trace elements. Fish naturally release Pheromones into the water column for a number of reasons but for this discussion, they act as a growth inhibitor. Simply put, without water changes, these Pheromones will accumulate and cause the fishes growth to slow and in many cases stunt them possibly causing deformation as well.
We hobbyists use Nitrate levels produced by the filter as a guide to help us know if we are changing enough or frequently enough. Most hobbyists don't have a Nitrate or NO3 test kit thus the frequency of this question. Now, I am unaware of any solid proof that Nitrate actually harms fish, rather it should be used as a guide to represent what other contaminants or waste products are also building up. NO3 will always be produced in your aquarium, it is a sign that your biological filtration is working properly. In planted systems the plants consume Nitrate but that does not mean we do not need to do water changes.
As a rule, we do not recommend a water change larger then 50% of the tank volume and no more frequent then daily. An average hobbyist will change 25% every week or two, sometimes monthly. In most cases it is not enough for optimum health for you fish.
There are Nitrate removing resins available in the trade but I don't personally support these products because by doing so you are removing your only guide to indicate weather your water changes are adequate or not. IMO.
Hopefully you have enjoyed the read.

[neven]

TDS is also an excellent indicator of when its necessary to do water changes.

[Rastapus]

TDS can be used as well but generally you would need a meter which the average hobbyist likely wont wnat to invest in unfortunately. It can be difficult enough to convince someone of the importance of a NO3 kit. For those willing to invest in a TDS meter, they work well.

[Otolith]

Now, I am unaware of any solid proof that Nitrate actually harms fish, rather it should be used as a guide to represent what other contaminants or waste products are also building up. NO3 will always be produced in your aquarium, it is a sign that your biological filtration is working properly.

Simply put, Nitrates may not cause direct harm to fish. However, with the break down of organics within the system, oxygen levels are depleted and from that the fish will be stressed. If the levels of Nitrates are substantially high, then enough oxygen will be used and fish will breathe at a more rapid pace just to compensate. As a result, they in turn use the remaining oxygen in the system even faster, potentially ending in death.

As an overall statement, I could not agree more.

[AquaSox]

What would you consider a high nitrate concentration? The EI (Estimative Index) target range for NO3 is 5-30 ppm in planted tanks.

Also what kits would you recommend?......since the cheaper (and more affordable) ones tend to be inaccurate unless calibrated with known concentrations.

[Rastapus]

What would you consider a high nitrate concentration? The EI (Estimative Index) target range for NO3 is 5-30 ppm in planted tanks.

Also what kits would you recommend?......since the cheaper (and more affordable) ones tend to be inaccurate unless calibrated with known concentrations.

Nitrate should be kept as low as possible as a gauge of other concentrations outlined originally but I personally feel a level between 20-40ppm is acceptable lower being preferred. I have found average test kits to be more then accurate since again, Nitrate is a guide used to gauge if you are changing water regularly enough.

[Fish rookie]

I do about a 50% (or a bit more sometimes) change once a week and I have a test kit (both the paper kinds and the liquid kinds that I purchased from your company). I cannot really vacuum the gravel because it is covered with plants so I am a bit worried if the decayed organic matters would harm the fish in the tank.
I just did a test today and my parameters are: Nitrate: 20, Nitrite: 0, Ammonia: 0, Ph: 7.6, KH: 80, GH: 60
I usually change my water on Sunday and today is Thursday.
Is there anything I should do like lifting the rocks and such and try to vacuum the gravels when I change my water?
I have put tabs in my gravel so I am also wondering if I vacuum the gravel would that kind of take out the fert for the plants?
What would you recommend?
Thank you.

[Rastapus]

I do about a 50% (or a bit more sometimes) change once a week and I have a test kit (both the paper kinds and the liquid kinds that I purchased from your company). I cannot really vacuum the gravel because it is covered with plants so I am a bit worried if the decayed organic matters would harm the fish in the tank.
I just did a test today and my parameters are: Nitrate: 20, Nitrite: 0, Ammonia: 0, Ph: 7.6, KH: 80, GH: 60
I usually change my water on Sunday and today is Thursday.
Is there anything I should do like lifting the rocks and such and try to vacuum the gravels when I change my water?
I have put tabs in my gravel so I am also wondering if I vacuum the gravel would that kind of take out the fert for the plants?
What would you recommend?
Thank you.

Normally with planted aquaria it is not recommended to do too much gravel cleaning per se, better to just remove the heavy debris from the surface. If not you risk disrupting your plant's roots. Sounds like your water changes are enough IMO, however with a planted aquarium it is odd to have any Nitrate present due to the plants using it as a food source. Is the aquarium heavily planted?

[Rastapus]

Most hobbyists do not change water often enough for optimum health and growth. In general once a hobbyist increases their water change volume or frequency, they notice within a few weeks the positive difference in fish growth and behaviour. On occasion customers will react that the more often they change water the more problems they have. If this is the case it is likely due to how the water change is being performed or absence of needed chemical/buffers not being added.

[Fish rookie]

Normally with planted aquaria it is not recommended to do too much gravel cleaning per se, better to just remove the heavy debris from the surface. If not you risk disrupting your plant's roots. Sounds like your water changes are enough IMO, however with a planted aquarium it is odd to have any Nitrate present due to the plants using it as a food source. Is the aquarium heavily planted?

The reading of Nitrate is not really zero but is lighter than the first reading which is 20 but it is not zero. I can try to do more water change (more often I mean) if you think there may be a problem.
My tank looks like this, not sure if you would call it heavily planted: