Re: phosphates off the scale

[Roger Miller <rgrmill at rt66_com>]

Ken Schaffer writes:

> my tap water tests ok for phosphates. i feed the fish "dried worms". i'm
> thinking maybe there are dead fish in the gravel. i did use ph down
> initially and then read that it has phosphates so i stopped. i have done at
> least a half dozen water changes since then w/ no effect on the phosphates
> levels. the tank is at my office so i can't run tests till monday... thanks
> for the response.

The pH down is most likely the cause of your high phosphates.  Phosphate 
buffers only work by overcoming the natural buffer in the water, which in 
many cases can mean adding 100 mg/l or more of phosphate.  You have to do a 
lot of water changes to get those numbers down to where normal hobby kits can 
measure them.

Another possibility is that your phosphate kit isn't working right.  That 
seems to be a common problem.

That said, I doubt that phosphate is really at the root of your problem.   
The "ugly brown algae" is a common phase during new tank break-in.  You can 
either let it run its course or you can add critters that will eat it; snails 
and oto cats (a swarm of them) are very effective.

Your description of the tank isn't very detailed, but generally the tank 
doesn't sound like a very healthy habitat for the plants.  With a pH of 8 the 
alkalinity (KH) would have to be pretty high or you don't have very much CO2 
for the plants.  Your bubble rate can be anything you want, but if the CO2 
isn't in the water then it does the plants no good.  Unless you can maintain 
healthy plant growth you will probably see a lot of algae problems.


Roger Miller