Tropical Fish Forum

Tropical Fish Keeping Help and Advice => Fishtank Filtration and Cycling => Topic started by: Cthulhu on February 18, 2015, 10:43:30 PM

Title: Tap water levels
Post by: Cthulhu on February 18, 2015, 10:43:30 PM

Is there any chemical or process that can reduce the nitrites in tap water? I have a large bin full of water ready for water changes, however the nitrite levels are just as high as the fish tank levels. I'm trying to reduce the levels in the tank but "bin water" isn't going to help.

Title: Re: Tap water levels
Post by: Helen on February 18, 2015, 10:57:40 PM

Do you mean nitrites or nitrates? And what level are they?

Real plants in the tank will use up nitrates.

Title: Re: Tap water levels
Post by: SteveS on February 18, 2015, 11:56:51 PM

Nitrites are dealt with by simple filtration.  If you have nitrites in your tank, your filter isn't working properly. Nitrites in your tap water should be below 0.5 ppm (the legal maximum).

Nitrates are more problematic. You can find nitrate filters but they are finicky and unreliable. The only sensible idea I know of is to use an R/O unit. (Reverse Osmosis).  These will remove the nitrates... but they remove everything else too! You end up with what is effectively distiilled water. You have to add back the stuff you want using remineralisation salts.  What is the level of nitrates in your tap water? It shouldn't be above 50ppm. And that should be OK.

Title: Re: Tap water levels
Post by: Cthulhu on February 19, 2015, 05:24:59 PM

I can confirm it is definitely nitrites not nitrates, using esha dip test stick. Which sponge would need cleaning in particular in filter as I dont want to wash out all just in case I remove too much bacteria.

Title: Re: Tap water levels
Post by: Sue on February 19, 2015, 07:35:06 PM

Just how high is your tapwater nitrite? The maximum permitted level in the UK is 0.1ppm, which your filter should remove fairly quickly.

If your reading is higher than that, either there is something wrong with your water supply or the dip tester you are using is giving you a false reading. eSHa's website implies that the tester can detect 0.3ppm as the lowest pink colour - this is 3 times higher than the maximum permitted level. Since dip testers are notoriously inaccurate, I would suggest this as the cause of high nitrite.

Title: Re: Tap water levels
Post by: Cthulhu on February 20, 2015, 08:40:18 PM

Hello all, so many thanks for all the responses, feel so daft I was looking at wrong indicator on test! Anyhoo 40% water change has improved fish happiness, sorry for wasting expert time.x

Title: Re: Tap water levels
Post by: Sue on February 21, 2015, 09:49:57 AM

It is easily done, especially when starting out. There is just so much to take in.