What To Do When Nitrates In Local Water Supply Are Already High

[Kaidonni]

I've just tested my local water supply and found the nitrates somewhere between 10-30ppm (darn Nutrafin liquid test kit is never that easy to read even under ideal lighting), and the tests turned out identical to one done on my tank water (performed others last night just on tank water, but under awkward light conditions). So, I don't need to worry too much about my aquarium's nitrate parameters, but if I wanted to lower them any more, I might run into a brick wall whereby I'm putting in what I've just taken out in terms of nitrates (it might be fresher water, but that isn't the point). Are there any products that might help reduce the nitrates in my local water supply prior to adding the water to my aquarium? Any other advice on the matter? I've contacted the water company asking for the parameters of the water supply, and if this might be a regular or seasonal variation, but apart from that, I suspect it's something that isn't going to change anytime soon. I'd assume 20-30ppm, judging by the tests, so unless I can do anything before adding water to the aquarium, I'm looking at 20-30ppm minimum as a constant when I test tank water.

 

[TallTree01]

Live plants consume nitrate.
I'd imagine there's some filter media Out there that claims to be able to remove nitrate, but such products for me have never worked for ammonia or nitrite so I don't see why they should for nitrate tbh.

 

[eaglesaquarium]

Purigen or zeolite does adsorb nitrate.

 

[daizeUK]

The nitrate in my water supply varies seasonally from 10-40ppm.  It's the reason I originally got into planting my tanks although they're now so heavily planted I actually need to add more nitrate, which kinda defeats the original purpose...
Anyway I wouldn't worry about it unless you keep or breed species that are especially sensitive.  30ppm nitrate is not going to bother most species.

 

[TwoTankAmin]

Purigen does not remove nitrate here is how SeaChem explain how the product might lower Nitrate:
 

 
Re: Purigen and Nitrates
There is a common misconception that Purigen removes such contaminates. This is not the case, Purigen controls them by removing the nitrogenous organic waste that is converted into these compounds. When using Purigen, people see their nitrates gradually drop and they believe that it is actually removing them when, in fact, it is actually removing the waste that causes them.

I guess it really doesn't matter if it controls them by removing the waste or the contaminates themselves, either way they are controlled.

We recommend removing any type of chemical filtration, include Purigen, when medicating. Chemical filtration medias can remove or otherwise negatively effect medications that are introduced into the water column. This can weaken the medication and make it less effective or render it completely useless. If the medication is weakened, the disease is given an opportunity to become resistant to the medication and we end up with a nasty disease that does not respond to normal treatment.

Controlling nitrates in a QT tank can be difficult when medicating. Generally, water changes are the best way to go about this. However, for the main tank, Purigen is a great way to control them and we have a great biological media that will support the proper bacteria cultures to remove the nitrates. Matrix provides both aerobic and anaerobic zones for bacteria cultures to colonize. This gives it an advantage over other bio-medias because it can support the entire nitrogen cycle. It works great at any flow rate and can be used in any type of filter. You can read more about it at the following link.

http/www.seachem.com/Products/product_pages/Matrix.html

from http/www.seachem.com/support/forums/showthread.php?t=3888
 
zeolite may or may not be effective for this purpose depending where and what your read:
 

 
Experimental results show that shallow‐well water (with nitrate concentration of 74–288 mg/l), after one‐hour mixing with 5 g of 0.315 mm particle‐sized zeolite and after 30 min. sedimentation, nitrate concentration stayed the same without any reduction. The same shallow‐well water (with 1–10 mg/l ammonium ion concentration) mixed with 5 g of 0.315–0.63 mm particle‐sized zeolite showed ammonium ion removal efficiency of 72–86 %.

from http/www.tandfonline.com/doi/abs/10.3846/1648-6897.2008.16.38-44
 
 
or
 

 
This study concerns fixed-bed column experiments performed at a laboratory scale in order to remove nitrate ions from water using a surfactant-modified (HDTMA+ = hexadecyltrimethylammonium) clinoptilolite as adsorbent. The influence of the initial nitrate concentration (0.32–2.42 mmol/L), the flow rate or flux (1.6–47.2 cm/min) and the presence of competing anions chloride, sulphate and bicarbonate, is examined. At the beginning of each experiment, removal rates R   are very high, larger than about 95%, and then decrease progressively during filtration. As expected, the higher the initial nitrate concentration and/or the flow rate are, the earlier the column becomes completely inefficient. In comparison to corresponding batch-wise experiments, the performances of the Surfactant-Modified Zeolite are better in the column in particular larger exchange rates values at complete breakthrough (≈60%).

 
from http/www.sciencedirect.com/science/article/pii/S1387181110004725
 
Note to get the better results surfactant nodification was used in the above research.
 
I would probably go with live plants or else a media that would host anaerobic bacteria as well as the aerobes to remove nitrate. An ambitious person might set up a holding tank for changing water with a veggie filter to remove nitrates before it goes into the tank.
 

 

[eaglesaquarium]

I stand corrected.  I read 'nitrogenous' waste as any nitrogen waste, which would include ammonia, nitrite and nitrate. 

 

[elmo666]

I have had the same issues as yourself, it can be a real pain as to a large extent it nullifies any benefits of a water change. I looked at may options, finally opting for a 3 stage reverse osmosis unit. What many of us focus on os the nitrate levels in our aquaria, because we assume they are mature and as such increasing levels of nitrate show a positive nitrogen cycle so we carry out water changes. The test kits aren't super accurate but they're certainly good enough to give us a baseline on which to know when changes are needed. However, tap water carrys a whole host of undesirable elements that are unbeneficial at best. Potassium, phosphate, magnesium, chlorine, chloramine, calcium, even arsenic to some extent. So, using r/o removes all these giving us a known base on which to work, one which can be accurately adjusted to meet specific requirements. Their cost is more than offset just in the savings made in dechlorinator alone over 12 months. The installation is straightforward, cost need be no more than £50 and the peace of mind in knowing no "nastys" are being added is priceless. Sinics will say r/o is missing the minerals needed, but it is easily corrected with the products available. I use pro discus mineral, run my system with co2, ph 6.5 and haven't had any issues with the much talked about "ph crash". So, in summary, if you have crappy tap water as I have suffered with, r/o is a good solution to the problem.

 

[Kaidonni]

Thank you for the replies. I haven't received a response from the water company yet, but then that's to be expected. I do have a lone Clown Loach I am trying to rehome (I intend to rehome, rather, but only the proper way - not a rush job), so I do have a sensitive fish. He has been around for a while (and a number of previous Clown Loaches who have since passed after a long battle against an unknown ailment, a situation I've extensively addressed in the appropriate forum here), so if it's between 20-30ppm, he's pretty used to it (another issue if I were to find a way to lower nitrates outside of water changes - I'd have to do it slowly).