Nitrate In Tap Water

[philak]

After doing some fairly large (25-40%) water changes over several weeks and retesting Nitrate levels each time i'm still at roughly 40ppm Nitrate by the API liquid test kit which is roughly what was indicated before the water changes. I finally tested the tap water and it's indicating somewhere between 10-20ppm Nitrate so hardly susprising that even large water changes don't have a dramatic effect!

I've done a search on here and the most i can find people talking about Nitrate wise in tap water is 4-5 ppm. Anyone else live in the Dorset area and get similar results to me? This is at my g/fs flat. In my home in Wilts the tap water tested at 0ppm for Nitrate.

I'm assuming a leavel of 40ppm will be ok becuase there doesn't seem to be any easy way to get the level much below that. The tank is well planted and everything is healthy , the only downside being some stubborn hair algae , even though im now using Seachem Excel liquid carbon. It was the algae that got me looking into Nitrate levels more closely.

 

[waterdrop]

Yeah, get on those Dorset water guys... how dare them allowing 20ppm nitrates in her drinking water! No, seriously, you won't get anything out of them I'm sure.

Forty or so is not going to be bad at all I don't think as its clear you are doing good maintenance and the system is only adding at most another 20 or so on top of the 20 coming in. I'd just up the water changes to 50% (nothing wrong with nice significant water changes!) and work hard at the substrate with your siphon! Most species of fish can take 400ppm nitrate and some catfish and others are apparently ok with 1000ppm! Besides, the most important aspect of acheiving the "only 20 above whatever comes in the tap" thing is that is helps verify that you are doing good enough water changes (with substrate cleans) to get all the 100's of others out of the tank that we do not have the time or money to measure! (we just measure nitrate because its relatively easier than most of those other problem things)

~~waterdrop~~

 

[philak]

Cheers chap. I didn't think it would be a fish killer at 40ppm.

I'd still be interested to know why some water authorities allow nitrates into the water whilst others obviously work hard to eliminate them .

Edit. According to the Wessex Water website the water quality shows a mean average of 33ppm Nitrate . Regulatory limit is 50 so they are pushing it a bit. No other measure of water quality in their list ( eg Aluminium ,Fluoride, Manganese, Lead) goes above 10% of the Regulatory limit but Nitrate is up at 66%.

 

[alchemist]

Its the nature of their water treatment plants - when they get an upgrade it would change

 

[Truck]

fertilizer run off from farms is also a major factor