Aquarium Forums UK

I had a couple of shrimp die the end of last week and when I did some testing I found the nitrates were up at 80ppm. Massive water change sorted this and got it down to 5ppm, everyone happy again.

4 days later and I test again and the nitrates are back up to 80ppm. I’m using TNC Complete, so I looked at the website and it says that f you don’t need nitrates to use TNC Lite but it also says it’s safe for shrimp and fish. I’m adding 0.5ml every day or 2 to a 25 litre tank, so within the recommended dosage. If it can raise the nitrates to those levels in 4 days, how can it be safe for fish, let alone shrimp?

Looks like I need to go the Lite route or have I messed up some where?

Just had another thought. I did also put some root tabs in. I was under the impression that those nutrients stayed in the substrate though.

Could be a mix of the two. Go a few days without the liquid ferts and then test and see what it comes back at.

What plant species and how many do you have in your aquarium?

fr499y wrote: ↑Sun Nov 28, 2021 19:30 pm Could be a mix of the two. Go a few days without the liquid ferts and then test and see what it comes back at.

Will do. Thanks.

Martinspuddle wrote: ↑Sun Nov 28, 2021 19:39 pm What plant species and how many do you have in your aquarium?

Java moss
Java fern
Hemianthus Micranthemoides
Lilaeopsis Brasiliensis
Pogostomon Helferi
Hygrophela Polysperma
Lobelia Cardinalis

walker26 wrote: ↑Sun Nov 28, 2021 20:05 pm

Martinspuddle wrote: ↑Sun Nov 28, 2021 19:39 pm What plant species and how many do you have in your aquarium?

Java moss
Java fern
Hemianthus Micranthemoides
Lilaeopsis Brasiliensis
Pogostomon Helferi
Hygrophela Polysperma
Lobelia Cardinalis

TNC Complete is high concentration fertilizer and is recommended densely planted aquariums, hence where your high readings are coming from and the plants you have are just not able to use all the fertilizer. I'm amazed you have not had one massive algae outbreak!

Do what @fr499y suggested, later I'd make up a quarter weeks dose mixed with some RO or deionised water and dose it daily. Start low and slowly increase the dosage as the plants grow filling the aquarium. Also what water are you using for your water changes?

If your using your tapwater which might have high nitrates, test it and adjust your dosing accordingly.

TNC Complete suggested dosage is 1ml per 10L of water per week.
So 2.5ml per week would be the suggested dosage for a 25L aquarium (or 0.33ml per day).
That is based on a heavily planted aquarium.

I would suggest dosing maybe only 25% of the suggested dosage (maybe even less) seeing as your only lightly planted at present and maybe gradually increase the dosage as the plants establish.
25% of 2.5ml is only 0.6ml per week or 0.1ml per day, you'll need a small syringe to measure that.

So my advise is to cut back the liquid fertiliser, a lot.

All the best

Just a side note, I always recommend TNC Lite no matter how stocked a tank is. I've never used complete, even on my seriously heavy, high tech planted tank ( But I do stock on the heavy side! )

I mix my own ferts and my tank is pretty heavily planted, I still don't need to add any nitrates as there's enough from fish food alone.
'Lite' fertilisers don't just leave out nitrates hence needing my own mix but they may work for you.

Sure, adding iron and others seperately certainly wont go a miss