I have a 55 gallon freshwater tank that is heavily stocked. All the fish are fine and healthy, but I have noticed recently that the nitrate level was outrageous. The reading said 180 PPM. I did a 50% water change the very next day. I just tested the water a little while ago, and the reading was 40 PPM.

I have been reading up on how to lower nitrate levels and the main answer is always PWC. I am looking for other alternatives that work as well. I read somewhere that you can add salt to the tank. I think it was 1 tsp per 10 gallons.
Another that I thought that I had read somewhere said adding vodka (???) to the water would help lower the nitrates as well.

I am perfectly fine with doing the PWC, because I don't want to get rid of my fish (knowing that I am overstocked). I just didn't know if anybody had any other input on other ways to lower the nitrates in the tank.

Thanks in advance.

Ideas to lower nitrate:-

1. More live plants - they will utilize the nitrates.
2. Keep tank clean - cleaner tanks produce fewer nitrates.
3. Careful not to overfeed - they will produce additional nitrates and phosphates.
4. I'm not sure if you can get it, but I use sintered glass media which harbors both aerobic and anaerobic bacteria which help reduce nitrates.
5. Keep up with the PWC's in all honesty that's the best way to remove excess nitrates and the fish will appreciate it too.

Hope this helps..