UK standard for nitrate is toxic for fish??

[Mike12345]

Been cycling a new tank for about a week and a half. I put some plants in it after a week, and after 3 days I've put 5 harlequins and 4 swordtails in it. Its a 200 l tank, so enormous, and a few tiny fish. After a day, the nitrate level is 40 to 80.

Thish shouldn't be possible from fish waste as there isn't enough time for the bacteria to build up enough to convert this. Which happens after about a month according to the research I've done. So I did some tests, nitrite is zero, ammonia is zero, still nitrate 40 to 80 ppm. I desperately started changing the water, which had no effect at all.

Then I tested the tap water.
Same red colour on the test sheet, between 40 and 80 ppm.

Then I checked the UK standard for nitrate levels in tap water. 50 ppm. Already toxic to fish. I've read posts about British keepers having die offs due to high nitrate levels in tap water, what do I do? I'm astounded that British standards are toxic to fish, and I've no idea how to fix it, as all the advice online is to do a water change to bring down nitrate level.

 

[Aiken Drum]

Water standards arent based on whats safe to keep fish in. And 50ppm isnt the standard. Its the minimum standard ie. the worst nitrate level allowable by law.

I read the same thing recently as i suddenly have nitrate in my tap water, but nowhere near your level. I was surprised that our UK/EU standard are are so poor when compared to US standards. I would consider contacting your water company and asking them for a nitrate level. These test kits arent that accurate, its not laboratory testing.

I wouldnt say 50ppm nitrate was toxic to fish, they can acclimate to much higher nitrate levels fine. What you might find is that moving fish from low nitrate to higher nitrate could struggle to acclimate. High nitrate might cause other issues though.

Plants soak up nitrate, so a heavily planted tank would benefit from your tap water and help to control it. You could also consider mixing your tap water with filtered RO water or bottled spring water to bring the nitrate down.

 

[Mike12345]

Thank you for your reply. I didn't think of contacting the water company, that's a good idea. I'm going to go to the pets at home where I got them from today, and ask what level their tap water is, if they treat it with something to lower nitrate, and buy something to try to reduce it.

A lot of what I've read online is that while high nitrate isn't anywhere near as bad as nitrite or ammonia, it can still stress the fish, cause weird behaviours such as aggression, or being subdued, and after a long exposure they can get quite ill due to those reasons.

I have some plants in the tank, but I've read some forum posts somewhere, where a lady had 50 ppm, and a heavily planted aquarium, and it reduces it to around 30, which is a lot better, but still not great for the little fish.

I feel guilty putting them in the water. I didn't test the tap water as I didn't think it would come out the tap like fertiliser lol

 

[Aiken Drum]

Dont get advice on fish from pets at home. They give terrible advice. Good for equipment and consumables. Fish are generally OK. Terrible advice.

I think they use RO water in their systems, so if the local water contains nitrate they won't be seeing it. Ask them what their water source is.

What area of the country are you in BTW?

It will be interesting to see if the nitrate removing products actually work. Keep us informed.

The biomedias that support anaerobic denitrification to reduce nitrate can take a long time to develop enough bacteria to be effective. I use biohome media that claims to support anaerobic denitrification, had it for nearly 3 years without any noticable effects on nitrate. Biohome say you should see reduced nitrate after a year. And if you go by their advice you need a lot of it. 1kg media/100 litres, so that needs a big filter for the size of tank to accomodate that much media. Check out pondguru youtube channel on this type of biomedia.

Then there are chemical products that make these claims of reducing nitrate. Trying to mess about with water parameters with chemicals often does more harm than good.

Keep us posted though. Will be interested to know if you have any success.

 

[Delapool]

Yes, seems a lot of work with products when I think plants could do a lot of the work for you.

I wonder why Uk is different - tap water here in Aus is generally very low reading in nitrates (if anything), although some local breeders complain of hills water (not sure on that one).

 

[Aiken Drum]

Yes, seems a lot of work with products when I think plants could do a lot of the work for you.

I wonder why Uk is different - tap water here in Aus is generally very low reading in nitrates (if anything), although some local breeders complain of hills water (not sure on that one).

I was staggered when i looked up the minimum standard a few months ago. EU standards are generally extraordinarily high. Now we have left EU we have temporarily adopted all EU standards into UK law while everything is reviewed. I somehow don't think we will now be improving on the poor quality standards, we will just see worsening standards of the ones that are good. Race to the bottom, woo hoo!

That isnt to say that all our water is poor quality. Thats the highest level of nitrate ive heard of here. Generally the standard is very good, its just the minimum legal standard is pretty poor. I recently saw my tap water go from 0ppm to about 5ppm. I might recheck it next time i do a round of water tests, see if its gone back.

While im on a brexit rant, im struggling to get a heater due to import issues from the EU. My local store that is normally pretty well stocked with equipment is down to about 6 heaters, none of which will heat my 200 litre and they have no idea when they will get more in. Ill have to go online.

 

[Mike12345]

I think the guys in the branch near me are quite knowledgeable. I'm in Basingstoke, the guys at pets at home said that quite a lot of customers complain about the water quality here regarding Nitrate. Different areas of the town have higher or lover though. They said theirs isn't too high, but not ideal. I bought a denitrifying sponge, which doesn't fit in my filter, so I cut it down, only to find that it's a basic sponge with a capsule of chemicals in it. I guess the sponge is supposed to make it slow release. I've got a giant tank so bought some denitrifying chemical to put in it too. I've done both, but the info is that it can take up to two weeks for it to take real effect.
Which is interesting as I'd be doing a water change and probably putting the nitrate back in by then...

I know changing water peramiters can do more damage than good, but I think it's important to make it so that the water isn't toxic, since every site I see says if its over 20 ppm for nitrate, do a water change. Ironically would make it worse as my tap water comes out like 40.

I checked with the water company, its 43.1 ppm for nitrate on their last standards check.

I bought a couple of moss balls today, hopefully they will eat some of it too...

 

[Aiken Drum]

Let us know if it has positive effect.