Dirty water

[Hillbilly nomad]

I've been feeding hikari carnivore for years with no problem. But in the last month or so the next morning my water has a reddish brown color. Instead of weekly water changes I'm doing them almost daily now. I've even bought extra hang on back filters for the problem aquariums. My 75 gallon has a 5 inch oscar, 4 inch kelberi peacock bass, and a 7 inch lima shovelnose. My 40 gallon has two 3 inch oscar, two 8 inch striped rafael catfish, and a 4 inch common pleco. The 75 has a 100 gallon hob along with a 40 gallon hob. The 40 has a 55 gallon hob along with a 20 gallon hob. Hikari is the only large fish food I can get in my town. Any suggestions would be more than welcome and greatly appreciated. 

[Native Keeper]

It may be that your original HOBs were malfunctioning, have you tried cleaning out the HOBs? when my 75 gets dirty, usually cleaning out the filter media helps clear up the tank.

[Colu]

As your fish have grown they are producing more waste that most likely what's happening switching food won't solve the problem with your stocking increase water changes and increasing your filtration   external canister filter might be better for larger  messy I had an external canister filter  and internal filter on my  Oscar tank  and did  water changes 2-3 times a week 

[Troy328]

reddish brown is a pretty unusual color, so I understand the concern. Is food going uneaten? Are there any fish that seem to have less of an appetite? Or as Colu has suggested, is there just more waste than before? Water tests might be able to help answer your question as to whether it is coming from fish waste/excess food or something else.

There's only a few other things I can think of that would turn water that color, and that would be tannins or iron. I'm pretty sure you would know if you had put something with tannins in your own water. Iron is also unlikely, but still possible. There could be rust in your pipes, or if you have a well, there could be more iron coming up from the groundwater than usual, although you would probably notice that your water throughout your home is discolored, not just the fish tanks.

Regardless of the cause, doing some tests, cleaning the filters a little, and continuing to do water changes can't really hurt. Best of luck!