If you do a 50% change each day, then 3 days, although that's assuming that your nitrates are not rising between the water changes. There's no problem doing a couple of 50% water changes in a day if you want.
You can buy Nitrate sponge from a better LFS and you can put that into the extra holder in your filter. (I also did that) but most will say it doesn't do much. It was worth a try for me. You are lucky if you haven't lost any fish due to the Nitrates, I lost several./QUOTE]
does anyone know how well the nitrate sponges work? if its worth the money i would add it as a buffer between water changes
I actually purchased a nitrate remover. It came in a bag you put in the filter. It didn't do a thing. There was another product--little rocks like carbon comes in---but I didn't want to spend any more money on band aids.
I'm getting results with the advice in this thread--thanks to all