High (ish) Nitrate readings

[strangemark]

Hi,
Tank currently up and running for around 8 months, test results are generally stable. Ammonia = 0 ppm nitrites = 0 ppm nitrates 40 - 80 ppm and there lies my problem! Water straight from tap sits at 40 ppm?

I would not say my tank is over stocked (5ft 300ltr):
Rainbows = 7
Cory's = 9
Khuli loaches = 5 (not that I get to see them too often 🤣😂)
L191 dull eyed = 1

Currently running aqua one external filter (looking to replace, came with tank), added a small internal filter to work as pre filter, as well as to improve water circulation.

My question is, what can I do to reduce nitrates closer to 0 ppm? Or this just not going to be possible with 40 ppm from the tap. Oh, forgot to mention, has plants, vallisanaria, Cryptocoryn balansai , Annubius, as well as mini monstera growing out of tank.

Any suggestions would be appreciated!

 

[hypnogogia]

My question is, what can I do to reduce nitrates closer to 0 ppm?

Why would you want to? Plants need nitrates to grow. Put even more plants in and they’ll take the nitrate out of the water, provided they have sufficient other macro and micro nutrients,

 

[strangemark]

Why would you want to? Plants need nitrates to grow. Put even more plants in and they’ll take the nitrate out of the water, provided they have succulent other macro and micro nutrients,

Hi,

Firstly thank you for your response!

What you state makes complete sense, however, will prolonged high (ish) levels of nitrates cause stress to fish? I appreciate that nitrates are not harmful to fish in the same way ammonia and nitrites are, but can they still cause stress for fish?

Kind regards

Mark

 

[Little]

Just to say, lovely tank you have!
Also, +1 to the recommendation to add more plants.

 

[Connswater]

reduce nitrates

I have had this problem, my tap water in the summer can be equally high in Nitrate. I discovered this after an algae outbreak following a big water change. There are some commercial products that will reduce Nitrate by chemical absorption, you add a bag of resin to the filter, many also reduce Phosphate, which may or may not be a tandem issue, but it is an expensive business and bothersome. I collect rainwater to mix with my tapwater, mainly to reduce KH but at times it helps keep Nitrate levels low - I aim for <10 but <20 doesn't seem to be problem ref. algae. I don't change a lot of water regularly, but I change less in the summer and sometimes top up with deionised water which is also free of Nitrate. And, I harvest floating plants, sometimes twice a week, frogbit, Indian fern, salvinia and hornwort, it takes about two months, but regular harvesting of floating plants will keep Nitrate levels low - assuming you don't add tap water full of Nitrate or fertiliser rich in Nitrate. Duckweed sucks up Nitrate but it is in my experience far more bother than it is worth...a water butt in a garage with tapwater and a cheap 100 watt floodlight light, about a foot above the water surface and with floating plants will also generate low Nitrate water, if you regularly harvest the plants and have patience, though of course plants grow more slowly when temperatures are lower in the winter, but in an insulated garage, particularly a brick one attached to the house, and you can get growth most of the year and I have had success in the past with this when I used to live in rural Kent and sometimes, just occasionally the tapwater was so high in Nitrate and Phosphate, from I suspect agricultural run-off, it was essentially unusable for a planted aquarium, and certainly no good for sensitive fish.

 

[bazz]

If that is your only problem then as already mentioned more plants. A couple of bunches of fast growing stems wouldn't go amiss, you can rid yourself of them later if they do not fit your final plan. You don't need to plant them either just weighed down in a bunch, you have a large tank so when they become too big just cut the top half off the bunch and repeat, two bunches. Adding a couple more emersed plants wouldn't hurt either if that is an aesthetic you are happy with, I don't do it myself but know they like Nitrate.

 

[dw1305]

Hi all,

Just to say, lovely tank you have!
Also, +1 to the recommendation to add more plants.

The advantage that plants have over other techniques for nitrate (NO3-) reduction is that you have a negative feedback loop, where more nutrients encourage more plant growth, reducing nutrient levels.

Cheers Darrel

 

[strangemark]

HI,

Thanks all for your constructive responses!

I will likely go the adding more plants route. However, as you may have seen there is a rather large L191 in there who decides if he likes plants or not 🤣😂

I have tried adding fast growing stems previously but the Cory's absolutely munch on them working there way up the stems. Anyway, I may buy some bunches of Limnophila Sessiflora to pop in and see how that impacts nitrate levels.

Cheers

Mark

 

[dw1305]

Hi all,

However, as you may have seen there is a rather large L191 in there who decides if he likes plants or not

Could you <"have floating plants">? They would get around the browsing / re-decorating issue.

Adding a couple more emersed plants wouldn't hurt either if that is an aesthetic you are happy with

That might be the way forward. Emersed plants have the <"aerial advantage"> of access to atmospheric ~ 425 ppm CO2 <"Trends in CO2 - NOAA Global Monitoring Laboratory">.

cheers Darrel

 

[Glass Box Diaries]

I will likely go the adding more plants route. However, as you may have seen there is a rather large L191 in there who decides if he likes plants or not 🤣😂

It looks like you already have emergent growing plants in the tank, if he leaves their roots alone you can try adding more as they can be a nitrate sponge.

The problem with that is balance as I ended up having to remove my Pothos as it was a little too good at dealing with nitrates and my submerged plants ended up having problems.

 

[Andy Pierce]

If your fish don't look stressed then I wouldn't worry about it. You can get into a lot of trouble trying to solve problems you don't actually have. Unless you think you have high nitrate because you have not completely controlled nitrites I expect you're good. That all said, more plants is always nice... you have to figure that since you're posting in UKAPS that is pretty much going to be the consensus view 🤣. In a big tank like yours maybe some vallis would be nice?