Do Fertilisers Increase Nitrates?

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Gary1962

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Hello

I'm always struggling to reduce nitrate levels.
Tap level is 20. Tank water often rises to anything from 40-80.
I use a liquid fertilser and Co2 daily 10ml each.
My aqua plant supplier insists the plants need both and that the ferts do not raise nitrates (but I'm mindful selling products is their business).
Anyone had any experience with this please?
Should I drop the ferts altogether and just use the Co2?

Tank stats below, if relevant:

What is the water volume of the tank? 180L

Does it have a filter? External and internal, each 600 LPH

Does it have a heater? 200W

What is the water temperature? 25c

What is the entire stocking of this tank? (Please list all fish and inverts.) 1 male betta, 1 starlight pleco, 6 sterbai cory, 6 rummy nose tetra, 8 harlequin rasbora, 11 cardinal tetra, 5 kuhli loach and 10 ammano shrimp.

Maintenance

How often do you change the water? Weekly

How much of the water do you change? 30%

What do you use to treat your water? Seachem

Do you vacuum the substrate or just the water? Substrate

Parameters

Did you cycle your tank before adding fish? Yes

What do you use to test the water? API liquid test

What are your parameters? We need the exact numbers, not just “fine” or “safe”.

Ammonia: 0
Nitrite: 0
Nitrate: 40-80
pH: 8.2

Feeding

How often do you feed your fish? Once daily

How much do you feed your fish? Two small pinches

What brand of food do you feed your fish? JBL

Do you feed frozen or freeze-dried foods? Freeze dried.
 

Wraithen

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Any good fertilizer will list percentages of what is used. If it has nitrate, it will list it on the bottle. If a bottle doesnt say exactly whats in it, it isnt a fertilizer, at least not one you want in a fish tank.
 

CanadianJoeh

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Your nitrates are pretty high.

I would do 2 weekly water changes of however much you're doing weekly, or change 2x the water you're changing once a week.

Ferts may affect your nitrates but in your case that is not the issue. Your tank is pretty heavily stocked.

Ferts don't usually present a nitrates issue. Ferts cause phosphate issues, more than anything, which if you already have high phosphates in your water, leads to more algae and can lead to cyano or Blackbeard algae.
 

Jerome O'Neil

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Your plants need nitrates, so you should expect to have some in there. I'd be surprised if your fertilizer didn't add any as well. 20ppm is a pretty decent amount, though, so if that is what is coming out of the tap, I wouldn't add any more if I could help it. Let the tank's nitrogen cycle do it's thing for a while and take your measurements after water changes without adding the fertilizer.

I agree with CanadianJoeh that your tank is pretty heavily stocked. If you don't want to reduce the bio-load, you might want to consider adding more plants, as they will remove nitrate from the system. Duckweed is particularly good at it.
 

DoubleDutch

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A lot of fertilizers don't contain nitrates and phosfates cause they are "automatically" produced in tanks. As Jerome stated plants need those as well and in fact adding fertilizers will cause plantgrowth and the intake of nitrates / phosfates that way. So in fact most ferts just lower nitrates/phosfates by making the use by plants possible.
 
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Gary1962

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Your nitrates are pretty high.

I would do 2 weekly water changes of however much you're doing weekly, or change 2x the water you're changing once a week.

Ferts may affect your nitrates but in your case that is not the issue. Your tank is pretty heavily stocked.

Ferts don't usually present a nitrates issue. Ferts cause phosphate issues, more than anything, which if you already have high phosphates in your water, leads to more algae and can lead to cyano or Blackbeard algae.
Really appreciate the useful information and advice here.
Hadn't realised my stocking is on the high side.
Being relatively inexperienced, have been using AquaAdvisor as my guide - see attached snapshot if their current numbers for my tank.
I'm currently using JBL Bionitratex JBL BioNitratEx
in my eheim external filter to try to manage nitrates - its the most effective product I've tried.
I'd struggle to swap out more than 60L on a weekly basis. Or do More than 1 water change.
So I guess it's either manage the stocking down by natural attrition. Or increase the planting density.
Plus the usual nitrate extracting sponge in my Juwel internal filter.
Screenshot_20190205-072115.jpg
 

CanadianJoeh

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I misspoke, your tank is what, 50 gallons? So in reality it's not that heavily stocked. However what you should have done is picked one or two species of schooling fish and put about 8-10 of each. The more they are, the more comfortable they'll be. If you'd picked one type, 16 cardinals look pretty cool you know.

That being said, AquaAdvisor is not a reliable source and should really just not be used.

Best websites for temperament and compatibility info is Fishlore (but the official info pages) in my opinion, and for temperature, care requirements, tank size minimum, etc, is easily SeriouslyFish, or Planet Catfish for Plecos.

More importantly - I reread your first post and you say your tap water has nitrates in it?
 
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Gary1962

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I misspoke, your tank is what, 50 gallons? So in reality it's not that heavily stocked. However what you should have done is picked one or two species of schooling fish and put about 8-10 of each. The more they are, the more comfortable they'll be. If you'd picked one type, 16 cardinals look pretty cool you know.

That being said, AquaAdvisor is not a reliable source and should really just not be used.

Best websites for temperament and compatibility info is Fishlore (but the official info pages) in my opinion, and for temperature, care requirements, tank size minimum, etc, is easily SeriouslyFish, or Planet Catfish for Plecos.

More importantly - I reread your first post and you say your tap water has nitrates in it?
Hey, thanks for coming back on this CJ! Good to have the ear of someone so experienced.

Really appreciate it.

Yeah, my tap water reads in the stronger orange range on API liquid test. So 10-20 ppm (I find their colour range difficult to differentiate - same at 40-80 ppm!)

Anyway, I've considered the route of RO water or a mix, before. But the cost and practicality rule that out for me. Also concerned about managing the fluctuation of PH in that scenario.

Can certainly see the advantages of a larger school single or two species tank. Including making it easier for temperature and PH compatibility.

Truth is, I wouldn't know any readily available route or re-home the other fish. And my current stock has been a great success as a peaceful community.

Thanks for the tips on information sources. Do any if those offer a similar but better tool to help judge stocking levels? Or is there a reliable way I can use to work this out for myself?
 

CanadianJoeh

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Hey, thanks for coming back on this CJ! Good to have the ear of someone so experienced.

Really appreciate it.

Yeah, my tap water reads in the stronger orange range on API liquid test. So 10-20 ppm (I find their colour range difficult to differentiate - same at 40-80 ppm!)

Anyway, I've considered the route of RO water or a mix, before. But the cost and practicality rule that out for me. Also concerned about managing the fluctuation of PH in that scenario.

Can certainly see the advantages of a larger school single or two species tank. Including making it easier for temperature and PH compatibility.

Truth is, I wouldn't know any readily available route or re-home the other fish. And my current stock has been a great success as a peaceful community.

Thanks for the tips on information sources. Do any if those offer a similar but better tool to help judge stocking levels? Or is there a reliable way I can use to work this out for myself?
Firstly,

It's my pleasure, we're here to help. Unfortunately since your water has nitrates, you'll have no choice but to either buy spring water at the grocery store or buy an RO system. You can get big jugs of spring water for cheap, though.

Secondly,

There is no "tool" for stocking unfortunately, it's just from experience. If you ever have questions just post to fishlore
 

bigemrg

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I've found that the best way of removing nitrate from my tap water (which is around 50ppm) is to use an under sink filter system produced by a company called Pozzani.

I also use the JBL NitratEx product and, like you, find it to be extremely effective.
 
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