Okay, so after a week or two of performing 50% water changes every other day to try to reduce my 40ppm nitrate level, I discovered that my tap is already running at 20-30ppm... I performed about a 75% change and replaced the carbon in my larger filter (Penguin 200) with Seachem De*Nitrate, but after a week (with one more 50% water change on one of the days) the nitrates are still steady at 40, even though the Seachem instructions said that the crystals should bring the nitrate down to 2-3ppm after about 5 days...

Since my tank is in my office and I'm using the tap in the ladies' room at work (hee), a filtration system is kinda out of the question. Do I have any options other than buying bottled water for water changes? I don't mind spending the money, since it looks like I may be able to buy in bulk; however, it's gonna be a bit of a haul to lug the water in from my car on water-change days...

thanks!!!

hmm.. I wonder if adding more de*nitrate would help... I'm already using a little more than the instructed dosage for my tank size.

Oh I hope someone can help you! I have the exact same problem. The nitrates in my tap are 20. And I really have no clue...

Are there any other taps you could try at work? Maybe there's something in the plumbing in the 'ladies' that might be releasing nitrates? is there a tearoom sink you could try? I find 'nitrasorb' pillows to work really well in adsorbing nitrates, unsure if that brand is available in your area. Other than that the only thing I can think of is bottled, or perhaps carting some from home. Sorry I can't help much, hope you find a solution!

Adding more of the Seachem De*Nitrate couldn't hurt. I'm trying a product called nitra-zorb at the moment. I'm kinda overstocked at the moment so it's difficult to tell if it helps. Fast growing plants may help if you have enough light. There are also anaerobic denitrification units you can build or buy.

I don't think 40 ppm is too worrisome. My tap is 20ppm and so my tank (after a weekly 50% change) is often at 20 - 30 ppm and has been so for years. Alot of advice out there says to start worrying at 100ppm, others say 50ppm and most agree that under 25ppm is ideal.

A heavily planted tank will keep nitrates down, naturally.

But again, at your levels, I would not start adding more chemicals to control it, just regular (weekly at least) water changes and good filtration.