phosphate

Question
hi just wanted to know why my phosphates keep going up even after i put in fresh phosguard my phosphate are at .3 will they ever go away for good sorry i am new to this i have a 75 gallon tank with a 20 gallon sump is there something wrong with what i am doing i do a 15 gallon water chang every sunday but when i put in fresh phosguard they go to 0 i change it every 3 weeks my tank is only 4 months old and i only have 2 fish yellow tange and clown i also have 90 pounds of live rock is that enough thank youy5

Answer
hello eric,

Where or how do you get your salt water for water changes?  also, what water do you use for FRESH water top off, (to replce evaporated water?)

typically , phosphates come from a couple sources...  

1/  the fresh water used to mix salt water... if it isnt filtered, ro/di water, or if the filters are old/bad, then phospates will come with the fresh water...

2,  fish food,, frozen cubes, the juice/water that comes in the fish...

although on a 75 gallon, that is not really a significant amount to be concerned about.

Im guessing it is the fresh water used to mix your salt water, or if you buy the salt water,  the stores filters are old/bad...

try testint the new salt water before you toss it in your aquarium???


good luck, and please keep me posted as to what you find out...


bill