Aside from the fact that goldfish are notoriously messy, you might be experiencing "New Tank Syndrome". How long has the tank been set up, especially the filter? The filter may not have had the time to go through the Nitrogen Cycle and develop "good bacteria" to handle the wasteproducts. Do you have an Ammonia/Nitrites/Nitrates kit?

"I have been changing water daily." I wouldn't do that, even at the 1/10th level you mention. The tank can't completely cycle if it's always seeing new water. (Unless this is an older established tank and the cloudiness is something new?) I'd also skip the tablets and miracle water remedies, they can do more harm than good as they accumulate in the water. My fish and plants have been thriving for years, their water is crystal clear, and I can't remember the last time I did even a partial water change -- I top up with distilled water so as not to keep adding more and more minerals from tap water, though. Anyway, let the tank completely cycle as "petiolaris" said, without doing any more water changes, and then things should settle down aside from the murk that your fish may stir up now and then as they dig around in the gravel. The danger is that the fish are going to get pretty stressed as the cycling occurs but goldfish are pretty tough creatures. Assuming, as I said, that this isn't an old tank that's suddenly acting weird! In that case a light green tint would suggest algae, which is completely harmless -- in fact fish seem to love the stuff...

- Steve Richardson
St Louis MO

I see that you have white gravel. Take it out. Never use white gravel or ornaments in your take as they give off a white cloudy haze. No amount of chemical or changing of the water will fix this. I had to take mine out completely even after trying to wash it thoroughly. Hope this helps. Robin