Issues with No2 and No3 levels.

I have a 105 litre tropical fish tank running now for about 4 or 5 months, I filled it with deironionised water as we don't have the best quality water in this area, currently I have 2 filters running in the tank, one is a tetra IN1000 modded the top chamber to have bio balls in it, and the other is a All pond solutions IF700+ with UV lamp.
All water levels testing perfect including ammonia and PH levels except for No2 and No3 which are pretty much off the charts, ive completed water changes several times and still spiking at dangerous levels, tried various chemicals to bring the levels down and they work for a couple of days and then they are back up, I'm only feeding every 2 or 3 days, and syphoning the substrate every weekend.
Any ideas on how to bring these levels down and keep them down without constant water changes, I'm not sure what's going on here and why they are so high all the time

A few questions.

Have you tested the deionized water on its own for nitrite and nitrate?

Do not use chemicals for this, as fish are present. It is OK to use Prime at water changes, but do not overdose and do not use except with a water change.

Which test kit? What are the numbers of the tests?

What is the substrate composed of?

The UV I am not sure of, whether it might affect this or not, others may know. Is there a reason you have UV? And what type/unit?

Edit, changed tap to deionized.

Byron said:

A few questions.

Have you tested the deionized water on its own for nitrite and nitrate?

Do not use chemicals for this, as fish are present. It is OK to use Prime at water changes, but do not overdose and do not use except with a water change.

Which test kit? What are the numbers of the tests?

What is the substrate composed of?

The UV I am not sure of, whether it might affect this or not, others may know. Is there a reason you have UV? And what type/unit?

Edit, changed tap to deionized.

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Yes I did test the deionised when I first started using it and put it in the tank, before adding the fish, the levels were perfect.

The chemicals ive used are mainly things like Tetra Nitrate Minus, Filter Active and Safe Start, ive never used conditioner as im not using tap water.

The test kits is Aquarium Lab multi test kit: this one: https://www.amazon.co.uk/dp/B00L5I8N64/?tag=

The substrate is White sand, (made sure this was cleaned as well as I could before putting it in the tank)

The UV is a sterilizer meant to kill harmful bacteria, a lot of people use them for cleaning up Algae, but thats not its only use, its an All pond solutions IF700+, this one: https://www.amazon.co.uk/dp/B00RZWGRA8/?tag=

I'm in the process of testing the deironised water out of the bottle now and uploading the results, the first 2 are below which are the quick 2 min tests, just waiting for the 10min tests to finish them will upload the Picts.

I will then do the tank water, same tests.

EDIT adding pictures

And now the fish tank water results

I will tag some other members who have better knowledge of this particular issue. @GaryE @Essjay @TwoTankAmin

While we are waiting, I do have a couple comments on the latest information. I don't know what the additives may do here, but the SafeStart may be involved; we have had other threads where using this has increased nitrite. The above members will deal with this.

I don't personally consider UV at all worth it in freshwater. It will kill bacteria and unicellular algae as you say, but only if all the water in the tank runs through it before the water returns to the tank. If that makes sense. Bacteria and all other forms of algae will remain in the tank and not pass through the UV. You cannot for example kill harmful bacteria in the tank; bacteria are sticky and adhere to surfaces, not float around the water. Again the above members will have more.

Byron said:

I will tag some other members who have better knowledge of this particular issue. @GaryE @Essjay @TwoTankAmin

While we are waiting, I do have a couple comments on the latest information. I don't know what the additives may do here, but the SafeStart may be involved; we have had other threads where using this has increased nitrite. The above members will deal with this.

I don't personally consider UV at all worth it in freshwater. It will kill bacteria and unicellular algae as you say, but only if all the water in the tank runs through it before the water returns to the tank. If that makes sense. Bacteria and all other forms of algae will remain in the tank and not pass through the UV. You cannot for example kill harmful bacteria in the tank; bacteria are sticky and adhere to surfaces, not float around the water. Again the above members will have more.

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Thanks.

I added start start as thats meant to contain the live friendly bacteria that helps the tank out and kill the no2 etc, doesnt seem to have worked though.

Tetra Safe Start is one of the recommended bacterial starters, but Nitrate Minus is a waste of time. It claims to promote the growth of bacteria which break down nitrate but I don't know of anything which removes nitrate that grows in the average aquarium.

I'm no expert - I let my last test kit expire in the 1990s...

I have used UV, to try to control the spread of Mycobacter marinum between generations with a rainbow I wanted to keep. I have a UV powerhead in my box of things I might use again.
I have friends in the business who use UV on central systems to slow or stop parasites.

Last night I filled an empty 25 litre bottle with tap water and added the required amount of aqua safe to it and a heater, this morning I've tested the water, the PH and ammonia is within the safe limits, there was no NO2 present in it, but there is NO3 present, not as bad as the results I'm getting from the fish tank water now, but it's still there, is it worth throwing this into the tank and then doing the same thing for the next couple of days resulting in a 75% water change ?

Goose3080 said:

Last night I filled an empty 25 litre bottle with tap water and added the required amount of aqua safe to it and a heater, this morning I've tested the water, the PH and ammonia is within the safe limits, there was no NO2 present in it, but there is NO3 present, not as bad as the results I'm getting from the fish tank water now, but it's still there, is it worth throwing this into the tank and then doing the same thing for the next couple of days resulting in a 75% water change ?

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Please give the numbers of all tests so we know. Ammonia and nitrite are zero, understood, but what is the nitrate of the tap water?

Byron said:

Please give the numbers of all tests so we know. Ammonia and nitrite are zero, understood, but what is the nitrate of the tap water?

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its about 20-30 ppm, I spoke to an aquarium store yesterday and they are going to give me some duckweed today to try and help control my nitrate levels, they said for now to stop using deionised water as it doesnt contain any KH which is also required to help the friendly bacteria grow, they also said in order to get the nitrite levels down, ive got to perform daily water changes of at least 25%, I did approx a 35% change yesterday and got a bottle heating up to do the same amount of change today, and stop cleaning my filters and substrate for a while to allow the good bacteria time to grow, also not to use the UV unless absolutely necessary, as yes it kills harmful bacteria, but also the good bacteria you want too.

I would not use duckweed - if you don't like it, it's just about impossible to get rid of it. One died out leaf stuck in a corner can regenerate a duckweed invasion.
I would try to find a different floating plant. You'll find them sold on many on-line sites including eBay (shops don't often stock them); look for salvinia, red root floater, water lettuce, Amazon frogbit, water sprite. Even elodea and hornwort stems can be left to float.

But plants only turn to nitrate if there's not enough ammonia to feed them. Plants help stop nitrate increasing by using all the ammonia made by fish, but if they get enough ammonia they'll have little impact on the nitrate already there from tap water. The shop got it half right when they suggested duckweed, but not the whole picture.

Essjay said:

I would not use duckweed - if you don't like it, it's just about impossible to get rid of it. One died out leaf stuck in a corner can regenerate a duckweed invasion.
I would try to find a different floating plant. You'll find them sold on many on-line sites including eBay (shops don't often stock them); look for salvinia, red root floater, water lettuce, Amazon frogbit, water sprite. Even elodea and hornwort stems can be left to float.

But plants only turn to nitrate if there's not enough ammonia to feed them. Plants help stop nitrate increasing by using all the ammonia made by fish, but if they get enough ammonia they'll have little impact on the nitrate already there from tap water. The shop got it half right when they suggested duckweed, but not the whole picture.

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Thank you, I will definitely look into getting something like hornwort.

About an hour ago I completed the 2nd water change, approx 30-35% of the water, nitrite is clearly coming down, and nitrate is slowly coming down, test results are below.

The nitrate in your tap water is an issue of its own. It is better to use pure water, not the tap, as this will avoid this nitrate. I assume the nitrate in the tank water is lower, if you are using the deionized water.

Byron said:

The nitrate in your tap water is an issue of its own. It is better to use pure water, not the tap, as this will avoid this nitrate. I assume the nitrate in the tank water is lower, if you are using the deionized water.

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I was using deionised water but have been told to stop using it as it doesnt contain any KH which is required for the good bacteria to grow, the shop I was talking to said I was worrying to much about the nitrate levels, when I should of been worrying about the nitrite levels and to go back to tap water, if you look at earlier pictures you can see that my nitrite levels were as bad as my nitrate levels, once I get nitrite right down, i'll sort the nitrate's.