London nitrates

Evening,
I've had to post a couple of items about fish dying, which led me to purchase an API liquid test kit, which revealed high nitrate:

After a bit of research I have my external filter a clean alongside 70% water change.

Afterwards I rechecked and it's still 20-40ppm.


I then began to question my water supply, according to Thames water in my area is between 27 to 37 ppm NO3 with an average of 32:

The permitted limit is 50ppm...

What fish can I get that will be ok with this, or do I need to get an RO unit if that would help?

Thank you,


Mark

How big is the tank, what fish do you keep and how much water do you change weekly?
My tap water comes out at 50ppm. I did have some success using a pozzani filter (search this site and the web).
Since I keep soft water fish as well I eventually gave up and did switch to RO. If you keep hard water fish the Pozzani could work for you.

You can also set up a large plastic container and fill it with tap water, then put some floating plants in it. Give them lots of light and let the plants use the nitrates up. When the water has 0 nitrate, use that water to do water changes on the fish tank.

Colin_T said:

You can also set up a large plastic container and fill it with tap water, then put some floating plants in it. Give them lots of light and let the plants use the nitrates up. When the water has 0 nitrate, use that water to do water changes on the fish tank.

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I've actually lots of floating plants in the tank, maybe they'll bring it down (water cabbages)

seangee said:

How big is the tank, what fish do you keep and how much water do you change weekly?
My tap water comes out at 50ppm. I did have some success using a pozzani filter (search this site and the web).
Since I keep soft water fish as well I eventually gave up and did switch to RO. If you keep hard water fish the Pozzani could work for you.

Click to expand...

It's a 4 foot tank, so I guess about 100l. At the moment just a small pleco, a platy, two cories and three small clowns.

Do you think this would be ok?
https://www.amazon.co.uk/dp/B0117A5TMU/?tag=

mhancock said:

It's a 4 foot tank, so I guess about 100l. At the moment just a small pleco, a platy, two cories and three small clowns.

Do you think this would be ok?
https://www.amazon.co.uk/dp/B0117A5TMU/?tag=

Click to expand...

No that would not help with nitrates. You could use one of these in one of the canisters https://www.pozzani.co.uk/product_info.php?products_id=67&q=nitrate instead of one of the carbon cartridges. That is exactly how I did it - but then I added a 4th filter to reduce hardness. All rigged up to a garden tap and you have to run the water through very slowly for it to work. The nitrate and hardness filters both needed replacing fairly often as these work on ion exchange. Your link is to what is effectively a standard pre-filter for an RO system (stages 1-3). So I just gave up and went to full RO. Bad news is I have recently chucked out a couple of those setups (I used to run 2 filter sets in parallel because it took so long).

On the fish side your platy needs hard water and everything else needs soft water. Your water is hard - so if you choose to keep hard water fish the pozzani filter is the way to go. Since you will be filtering slowly you may as well use the carbon block and sediment filters as it will make your water (a lot) cleaner and you won't need to use dechlorinator. If you choose to stick with soft water species ... well I have chosen the ro route.

Thanks for the reply.

I'm wondering about getting this, but using the nitrate filter after the chlorine one:

Call them and discuss what you actually want and what you need to achieve. I found the guys there to be really helpful and they do know their stuff. As an example the one in your link uses 1/4" push fit connectors while the standalone nitrate unit is sold with hosepipe connectors. It will also save you from paying for cartridges that you don't want.

Also they are just standard 10" cartridges. I found the Pozzani housings to be great quality and never had one leak, and never needed to mess about with it to stop a drip, but they are expensive. I ended up with a mix and match system when I saw how much cheaper the housings were on amazon.

Have you thought about using Purigen? That’s all I use to help reduce the Usual nasties.

Lunar Jetman said:

Have you thought about using Purigen? That’s all I use to help reduce the Usual nasties.

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Oooh, jet pack!

I've not heard of that before, just looked on Amazon. I guess you put it in the external filter?

Seems odd that you'd clean something with bleach though and then put it back in the filtration system, if I've read that right....

mhancock said:

Oooh, jet pack!

I've not heard of that before, just looked on Amazon. I guess you put it in the external filter?

Seems odd that you'd clean something with bleach though and then put it back in the filtration system, if I've read that right....

Click to expand...

Yep, you soak it in bleach to recharge it and after rinsing, put it back in the filter. Really good stuff and makes the water crystal clear.

Actually, I’m just about to soak some in bleach myself to recharge it.

Definitely helps to bring down Nitrates amongst other things.

I've ordered this, more than enough for my tank and could work for 6 months:
https://www.amazon.co.uk/dp/B0002A5VK2/?tag=

As it's only £11 if you don't need quick delivery, I'll just replace it rather than have the hassle, and more importantly risk, of using bleach.

Given that nitrates are so high in local water, I guess it would be better to do small water changes to avoid a nitrate spike.

If I did 20% changes, could the purigen cope with the chlorine? Normally I'd not use prime for a change that small.

Be wary of marketing claims. According to their website Purigen® controls ammonia, nitrites and nitrates by removing nitrogenous organic waste that would otherwise release these harmful compounds. It does not remove nitrates . I used this for several years. Its a great water polisher but will not lower the nitrates from high levels in the tap water.

It was that description that persuaded me to buy it - let's see what happens.

Plan B would be a two cartridge filter system to remove Chlorine and Nitrate for water changes.

I've had the purigen in for nearly 18 hours now - it seems to be dropping the nitrate a bit. Be great if it does, as advertised, remove it completely: