0 nitrAtes question

hi , I have a 5g q-tank which is cycled , all the fish have gone to their planned tanks and want to get more fish.

The last fish were removed 2 weeks ago and i have a reading of a-0 , ni-0 and na - 30.

When i called the aquarium store to see if they had what i want, i mentioned the na was 30, but will do small wc;s to get it to between 5 and 10 before purchasing the fish. The guy said i should have 0 nirtAtes before adding fish. I have no plants so I never get it to 0, not even my 54g which i do daily 10% wc's ---usually that one runs between 5 and 10 for nitrates.

So what is this guy talking about ? The fish I want are not that sensitive that na -10 would kill them . ????? Why was he so adamant about having 0 nitrates ? thanks

He probably doesn't know what he's talking about. You often hear those unfamiliar with water parameters (or just marginally) say that everything should be zero. Well, anyone who's run a tank and tested frequently knows that zero nitrates is hard to get without live plants or nearly constant large water changes and low stocking levels. Either that or they confused nitrites for nitrates. Funny, now that I've gotten more into planted tanks I actually add nitrate to my tank, aim for 25ppm or so a week. Granted its spread out over the course of a week and the plants take up some, but the fish show no ill effects, in fact fish appear better than in non-planted tank. I wouldn't worry about it.