Npk Ferts And Nitrate Test Readings?

[Electric Warrior]

Hi, someone put my mind at rest! So, I have planted up my tank a bit more recently, and I have started dosing liquid carbon to give my plants a boost. Before I was using the carbon, I was dosing TNC Lite, but have since changed to TNC Complete for the NPK. Now my question arises from the fact that my nitrate reading in my tank was always under 20 before, but now I just tested everything after dosing ferts about 24 hours ago, and my nitrate reading is 40-60ppm! Obviously I was a little surprised as I thought that the plants would have eaten far more nitrate than that? I am obviously a bit worried about this level for my fish, but are my nitrate readings so much higher purely from the TNC Complete, and is it the same sort of nitrate that you would get from nitrogen cycle or is it different? I have. 200l and am only dosing 3ml a day. Is this normal or should I do something different?

 

[DrRob]

The simple answer is that most high tech planted people ignore test kits unless something doesn't look right. With regards to the cycle, nitrate in the water is held ionised regardless of the cause, however some organics will bind things better than others, so the fertiliser may be more available to the test kit.
 
Overall, don't worry about it, just do sensible weekly water changes if you're doing high tech.
 
That reminds me, I haven't fertilised my tanks this evening yet, thank you.

 

[Electric Warrior]

Okay thanks for that. I usually perform a 30-40% wc, which I think is okay? I don't know if I am considered high tech though, as I have pretty low light, around 1.15 wpg, as I only use the t8 tubes that are able to fit in the Roma? I would love to upgrade to t5, but still have not had the opportunity to do so yet, so I know my plant growth is going to be somewhat limited under this setup currently. I have also been using half the recommended dose of carbon because I do have vallis, so we shall see what happens. This is really my first planted tank, so I have been struggling to find the proper balance between flow, c02, ferts, lighting, etc. I fell that I have how the ferts and flow down pretty well now, it's just my lighting that I am going to have to bring up to par . I was just a bit worried about the nitrate reading because I have a sensitive apisto. After my wc my reading was somewhere between 10-20 ppm about two hours after dosing ferts, although I find that anything above 5 is nearly impossible to read with the API kit!

 

[Electric Warrior]

Another question: if I am concerned about nitrate levels, can I continue to dose liquid carbon if I use TNC lite, in addition to added phosphate from say, Seachem Flourish Phosphorus for example? I may or may not need additional potassium too? TNC lite contains only 1%k, where the Complete has 5%. I just feel that my plants get more than enough nitrate from my fish tbh. If I still want to dose carbon but not nitrate, will something like this work?

 

[SO19Firearms]

Another question: if I am concerned about nitrate levels, can I continue to dose liquid carbon if I use TNC lite, in addition to added phosphate from say, Seachem Flourish Phosphorus for example? I may or may not need additional potassium too? TNC lite contains only 1%k, where the Complete has 5%. I just feel that my plants get more than enough nitrate from my fish tbh. If I still want to dose carbon but not nitrate, will something like this work?

 
In theory yes.
My main concern would be you relying on test kits - Total waste of money. But beyond that, wait for any Nitrogen deficiency and take it from there,
 
IMO

 

[Electric Warrior]

Okay so in theory what would be a good dosing regime for me, assuming I would like to continue dosing some liquid carbon, but not any more nitrate? I am moderately planted, around 50% I would say, but well stocked fish wise. My light is on the low side, at about 1.2 wpg. I have several crypts, some swords, vallis (which seems okay so far), ludwigia, Pygmy chain sword (which is doing really well), some mosses, and some hygro and some frogbit, and water lettuce. I was currently dosing 3ml of liquid ferts (tnc lite or complete) and 2 ml of easycarbo a day. I also use api root tabs. Decent flow in my tank, as I run two external filters and use a powerhead.

 

[Electric Warrior]

Just FYI, my main concern about this arose because I will be housing a couple of adult discus in this tank in another 10 days, so I immediately became concerned when I saw 60-80ish ppm of nitrate on my liquid test the other day. So am I worrying over nothing? I have only been dosing easycarbo for about 2 weeks now, but my plants (minus the egeria as I somewhat expected) are already looking a bit better, and algae issues are already clearing up. I want to have a lovely planted tank, but my main concern is the discus that will be going in my tank.

 

[SO19Firearms]

Organic Nitrate is different to adding inorganic Nitrate via a fert as the Nitrogen cycle hasn't played a part (IMO).
So while I would generally say adding ferts (with Nitrate) won't be a problem I can't say how sensitive discus would be to the organic process...so you might want to consider water changes to get your natural nitrates down and if you wish (or your plants need it) add some inorganic back back.
I'm not advocating the use of test kits still...but maybe 30ppm would be better for your discus
 
 
 
Bear in mind I really don't believe it's the 'high' Nitrate value that leads to problems, it's whatever is involved to get that value.

 

[Electric Warrior]

Okay totally understand. What about liquid carbon though? If I choose to stop dosing Complete, and go back to Lite, will I still be able to use easycarbo at half the dose? Assuming my nitrate stays at about 30, and I believe the API root tabs I use contain macro's, although I am sure that the amount is probably lower than liquid fert? Sorry for all the questions but this is my first planted, and trying to get the balance right is a bit difficult, and now obviously the discus are going to be my main concern. Do I need to add any addition phosphate for example, via liquid like Seachem for example, or are root tabs going to contain enough? I know that phosphate can be bad for fish in too large of quantities. Obviously all the nutrients from the root tabs are in the substrate, rather than the water column. So, can I still use liquid carbon while using root tabs and TNC Lite, or add additional macros and see how everything goes? Or, forget carbon all together?

 

[SO19Firearms]

If you use Carbon you should be using a complete fert IMO.
Whether you choose to use Carbon or not is governed by your lighting. It's more a case of you need it, or don't. More than should I use it....
 
EDIT: I've realised that all my posts are a bit criptic and you'd probably rather hear "do this and do that and it will be fine" - Unfortunatly IMO one size doesn't fit all - It's probably best you jump in and give it all a go....

 

[Ps3Steveo]

^^^^^^^^^^^^^^The force is strong in that one ^^^^^^^^^^^^^^

 

[Electric Warrior]

Okay help me out to see if I am on the right track here... I have established that I have low light, and flow in my tank is good. I would still like to dose some liquid carbon for that little bit of 'mphhhh.' Since I have staring adding it I have noticed that most if the algae problems on my plants are gone, although glass is still getting some of that brownish algae that gathers in spots and blurs it up. I simply wipe it off. I really want to try and maintain my nitrate at about 20-30, correct, and it doesn't really matter whether it is through the breakdown of fish waste/food? Or if I add it to the tank via liquid fert?

As far as I understand, I therefore should aim to keep phosphate levels at 2-3? Now with regards to K, is there even an easy way to measure levels in the tank, other than looking for K deficiencies in the plants? Is it true that it is relatively harmless to add to the tank at fairly liberal levels?

Last question, as I was expecting, my vallis is starting to melt from the carbon; at least most of the new growth, as the old growth seems to be doing fine for some reason? Are there any easy background plants that will survive liquid carbon, that I can grow in higher temps of around 28C?