I am going away for about 9 days, I don't have a problem having my tanks fed, have trained geriatric father, and he does not overfeed, My question is, will my community tanks be o.k. for an extended period, without water changes? I used to test every week, and had Nitrite readings of zero, and nitrate readings of around 20, after seven days, so now I don't bother testing! Tanks are established, and with 25% water changes on a weekly basis, all is cool. I am thinking of doing a 50% water change on each tank, the day before I go, in the hope that this will tide them through until I get back, what do you collective guys and guyesses think?