nirates in tap water

[bre'r lappin]

Hi -
I am the owner of a 55 non-planted aquarium stocked with various catfish.
I've been battling a nitrate problem for some time now, despite frequent water changes. On a whim I decided to test the water straight out of the tap and it registered at about 20ppm. Is this normal? Could that be contributing to my problem, or is there something about straight-out of tap water that causes false readings (I read that sometimes the pH can be off due to bubbles or somesuch)?

I'm a bit confused here.

[snakeskinner]

according to the aquarium store I use I'm too stupid to figure out nitrate levels anyway, hehe. That is possible but you need to contact your local water department because this is usually a condition they post flyers around town and try to remedy. Try using distilled water. I thought this would be too much trouble until I broke down and went to the store and found distilled water at 53 cents per gallon so I bought enough to do a water change and it works great. It's not near as expensive as I first thought. Plus, it's a lot cheaper than fish. I'm no expert at this either so don't take my advice over anyone else's. Kyle

[OrionGirl]

Nitrates in the water is common in many areas. You could get a reverse osmosis filter, purchase filtered, or add some floating plants to reduce it.

However, before getting too wound up about it, nitrates are not harmful to most fish. As long as you are doing regular changes to remove the other compounds that build up, and the fish are not showing stress, I probably would not make any changes.

[bre'r lappin]

Thanks for the replies.
The nitrate usually hovers around 40ppm, which I thought was pretty high but the fish don't seem stressed out, so I think I will just continue keeping the tank as I have been and not worry too much.

[JSchmidt]

Nitrates in tap water aren't supposed to exceed EPA limits of 44 ppm. Nitrates in tapware are mostly dangerous to babies, but it's probably better for us (and our fish) to avoid chronic exposure to much higher levels.

By itself, tapwater with 200 ppm nitrates isn't a problem. We use nitrates in our tanks more as a general marker for pollutants that aren't so easily measured. Instead of trying to keep nitrates in the 20-40 ppm range, you may have to adjust and shoot for 40-60 ppm. Your fish should be fine.

You can use RO water or a nitrate-absorbing compound, but unless you're keeping some extremely sensitive creatures, that's not necessary.

HTH,
Jim