Nitrate issues

[axl10]

Hi Guys,
I'm currently cycling my 1600ltr tank and have got a question about nitrate. My tank is showing up nitrite as a purple colour one day and then the next day its blue. But there is no nitrate colour showing up yet? Also i have started dosing 4 tablespoons of Potassium Nitrate in the tank and i still can't get the nitrate to raise and this is a new API Nitrate test kit. I tried some KN03 in a glass of water and tested it straight after and still no nitrate. Whats the go with this?


Cheers Axl

[Filip]

I think that you have to feed the bacteria with pure Amonnia to achieve fishless cycle , not KNO3 . Nitrate with this method as i recall should start showing on test after 14 day from the beginning of the Amonnia feeding proces .
Hope others will help more here. Our fellow member Dan-DJW is excellent in chemistry, so maybe he will chime in , and in the meanwhile type fishless cycle in the browser here and you will get many threads and answers on this topic.
HTH.

[axl10]

I think that you have to feed the bacteria with pure Amonnia to achieve fishless cycle , not KNO3 . Nitrate with this method as i recall should start showing on test after 14 day from the beginning of the Amonnia feeding proces .
Hope others will help more here. Our fellow member Dan-DJW is excellent in chemistry, so maybe he will chime in , and in the meanwhile type fishless cycle in the browser here and you will get many threads and answers on this topic.
HTH.

I have got 8 fish in there while the tankis cycling and i have had ammonia readings 2 weeks ago and now that is zero. I'm only getting purple with the nitrite one day and the next day its blue. I'm adding the Kn03 for the plants to try and get the nitrate up. Maybe the plants are using all the nitrate that is getting available in there

[Filip]

Axl , don't know the chemistry behind your test readings but I do know that you don't need to add KNO3 for plants in an uncycled tank . Plants utilize ammonia and nitrites even more readily and with bigger ease as they do with nitrates .
So the only thing you should worry about right now is the water quality and your fish health , and do some more waterchanges.

[DJW]

I can't figure out how the nitrite can be gone one day and back the next (if that is what you have seen)... unless you are dosing the tank with ammonia, which you wouldn't do with fish in the tank. What is the nitrite now? The only way nitrite can disappear is by being converted to nitrate by the filter, or siphoned out with a big water change.

The contents of bottle #2 of the nitrate test settles and sticks to the bottom, which is why the directions say to shake it for at least 30 seconds. Maybe it has been sitting on the shelf a long time. Try banging the bottle against the table and shaking it really good, then see if it reads nitrate from the potassium nitrate. If that won't work, try a new test kit.

Not sure how much a tablespoon of potassium nitrate weighs in powder form, but 4 tablespoons of potassium nitrate in 1600 liters works out to around 40 ppm of nitrate. If you have added a few of those doses, the nitrate might be sky high.

Filip is right about adding this fert, the plants will readily take up the ammonium.

[axl10]

Thanks for the info mate the current reading of the nitrite this morning was a light blue colour. Should i do a 50% wc to get the nitrate levels down as i added 4 tablespoon of kn03 last night and another 4 this morning. It was mean't to be teaspoon and i have currently got goldfish in there. If i do a water change will this affect the cycling process? Obliviously the reading is through the roof and is off the chart. Would you suggest I do? I have only got low light plants like swords, ferns and anubius what fert program should I look at using? I'm running led light on the tank at the moment. Any help would be greatly appreciated

[DJW]

On the API color card light blue indicates 0 nitrite, so it sounds like the cycle is done. Watch the nitrite, it should stay at zero now.

Changing water at this point won't disrupt the cycle. Before you add any discus you want the nitrate down below 10 ppm... 5 ppm would be better.

I don't know much about fertilizers, my plants seem to do well enough without them being added.

[DJW]

By the way... using goldfish is a risky way to cycle a tank. Its much safer to use the fishless method with ammonia. Have your grow-outs already been exposed to the goldfish?

[axl10]

By the way... using goldfish is a risky way to cycle a tank. Its much safer to use the fishless method with ammonia. Have your grow-outs already been exposed to the goldfish?

They will be going in a week as the ottos, cherry shrimp and cory sterbia are going in there. My discus haven't been exposed to these goldfish at all. I will be selling them shortly

[Akili]

They will be going in a week as the ottos, cherry shrimp and cory sterbia are going in there. My discus haven't been exposed to these goldfish at all. I will be selling them shortlyAfter selling the Goldfish and then adding Discus and other tank mates in the same tank is very risky. A very high chance of cross contamination.Do a fishless cycle as recommended by others and make sure all other tank mates go through a proper quarantine procedure.

[Filip]

After selling the Goldfish and then adding Discus and other tank mates in the same tank is very risky. A very high chance of cross contamination.Do a fishless cycle as recommended by others and make sure all other tank mates go through a proper quarantine procedure.

+1 .
If you are spending a lots of money for a big batch of quallity discus , you might wanna secure your investment and start brand new with a sterilized tank , and a fishless cycyle.
This way the pathogens that inhabits Goldfish system might very well still be in the water even after you remove them, and attack week imune systems of your newly introduced discus .