I've got a 60 litre tank with guppys & mollys & swordtails. I do a water change weekly & I "Hoover" the stones & wash the filter in removed tank water. But my tank seems quite dirty. It's ok when it settles, but when the stones move, loads of "crap" comes out. The fish are not over fed. But it was 3 months before I got a "Hoover" for the tank as I just did what the aquarium centre told me. And just used what they sold me. It was nky going on a fish forum & seeing vacuum discussion that it occurred to me. Have I got a build up of "crap" in the bottom of my tank.
Oh, the fish breed like stink. I should get a fry tank really.
I only have a small tank with some tetras and harlequins at the moment (32l). I did nothing to my tank for 2 months as I was too ill and DH was occupied keeping the kids and the cat going. I have just had to do a "kill or cure" full water change and empty the tank completely and clean all the stones and scrub the glass. I was amazed at the crap at the bottom - they were definitely not overfed, as only I feed them, and I was only managing every few days. BUt there seemed to be large chunks of stuff. But they all survived the complete change , I'd prepared the kids for some fatalities, but they are clearly hardier than they're supposed to be!
Debris in the stones is entirely normal but can obviously be minimised by regular hoovering. My tank is crystal clear and very clean, I've finally got my plants sorted and it looks great . But when I clean it out you would not believe the crap that comes out, the water comes out nearly black - I blame the plecs
I would never do a complete clean personally, the gravel contains a huge amount of bacteria that your tank needs and you would basically be washing that away and leaving just the filter media which would be like cycling with fish to all intents and purposes. The majority of fish would most likely survive but it's a lot of stress on them. Twice weekly hoovering would be better
Sounds to me like it's just over-stocked; how many of each fish do you have in there? I've got a 60 litre tank and all I have in there is 8 cherry barbs and a few shrimp. It's very manageable to clean. I like to stock lightly though because I'm too lazy to do more than one water change a week
Yes, aspie is right, a complete clean is a bad idea and shouldn't be needed in a properly stocked and maintained tank anyway. Most of the good bacteria is in the filter though, because it needs a constant flow of oxygen.