# Nitrates, tap water and plant aborbtion



## idris (31 May 2011)

If adding tap water with relatively high nitrate levels when doing water changes, how quickly will they be taken up by plants? 
What are the effects on fish during such nitrate spikes?
How do these spikes compare with those resulting from adding ferts?
Should you consider some way of reducing nitrates in the tap water, and if so how?


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## Bobtastic (31 May 2011)

The CEG will tell u not to use the test kits as they are inaccurate and can be miss leading at best.

As we in the planted tank world happily add large quantities of nitrates why would free nitrates in the tap water be a concern?


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## idris (1 Jun 2011)

Both good points well presented. 
Irrespective of the test kits innate accuracy, I find them potentially accuracy on the grounds of "well, it could be grew, or yellow, and that red is nothing like the reds on the chart". That said, IMHO they do at least give some indication of which extreme the water stats may be nearer to. Which is somewhat useful at set-up, or tomes of problems. (I will be searching to see Ceg's suggestions on this.)

As for the actual issue, that's not something I'd bought of. But it does increase my interest WRT fish response to sudden changes in nitrate levels nitrates, be they from water changes or ferts. And I am now interested in the relative concentrations of nitrate being added in ferts. 
(O blahblahblahblahblahblahblahs! More biochemistry. New forum signature...)


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## niru (1 Jun 2011)

Hi idris

I would have tended to agree with you regarding the tests as indicators of the water chemistry, but I have experienced myself (& also read here many times as stressed by Ceg & others) that these tests arent very accurate with hobby-level kits. The fluctuations you might see are too large to explain easily without going into gory details.. Thats why I have stopped using these kits /&wasted quite some money on them).

However I havent been able to really understand why these chemical tests go bonkers when we use them in tanks (scientific reasons as such). I recall from school days that we use similar tests to determine chemical analysis of solutions (using same drop counts, titrations, pipette measurements, etc etc.) Those times these seem to be ok, but when trying to bracket a ppm concentration level, they fail miserably. WOuld be nice if someone could point any links as to why, and given these, why manufacturers still make & advertise them (of course the sales goals etc etc..), but why "cheat" in an already expensive hobby?


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## idris (1 Jun 2011)

*Original question changed to keep the tread on topic.*
Thanks for the responses though - useful food for thought.


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## bigmatt (1 Jun 2011)

It's difficult to establish a causative link between nitrates and fish health.  In the non planted world nitrates are often a result of poor tank maintenance - so nitrate build up = lots of other nasties in the water = poor fish health.  Then the "leap" is made that high nitrates=poor fish health.  In truth, only by analysing tank water in lab grade equipment that identifies EVERY chemical component of the water can any link be made, and i bet you a tenner nitrate wouldn't be to blame.  In terms of nitrate shift during water change again, it's a difficult parallel to draw.  Tap water contains all sorts of things (for example i know of people who have lost loads of shrimps at water change through copper contamination from their hot water system and also through traces of pesticides being present in rural areas) so it probably won't be the nitrate that causes the issues, but something else.  I know your tanks is HUGE so if you do your water changes with 9mm tubing it gives your fish chance to acclimatise to the new water anyway, and i've never had any fish deaths doing it this way
Hope this helps mate and i haven't completely missed the point!
Matt


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## a1Matt (1 Jun 2011)

idris said:
			
		

> If adding tap water with relatively high nitrate levels when doing water changes, how quickly will they be taken up by plants?


Uptake rates vary a lot from tank to tank, hard to say. There is data for this over on Barr report (I think it is in the EI and non co2 methods tutorials).


			
				idris said:
			
		

> What are the effects on fish during such nitrate spikes?


No effect.


			
				idris said:
			
		

> How do these spikes compare with those resulting from adding ferts?


Same, no effect on fish.


			
				idris said:
			
		

> Should you consider some way of reducing nitrates in the tap water, and if so how?


No.  You definitely should not 

Nitrates are not harmful to fish. Not at all. (They just contribute to your TDS, which in a planted tank only matters if you have super sensitive fish or are breeding certain species.)

Ammonia is bad.   If your tank has an ammonia spike, this will then get turned to nitrate.  So bad things happen, then nitrate is found at the scene of the crime shortly afterwards.  Poor old nitrate then gets a bad name


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## Fred Dulley (13 Jun 2011)

Have a read of what Clive (ceg) has to say here
viewtopic.php?f=21&t=12592&p=132788&hilit=nitrate#p132788


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## greenink (18 Jul 2011)

Fred Dulley said:
			
		

> Have a read of what Clive (ceg) has to say here
> viewtopic.php?f=21&t=12592&p=132788&hilit=nitrate#p132788



That's an incredibly helpful post. He really should write a book.


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