Performing Large water changes

[NanoJoe]

I am considering doing a large water change this weekend as i heard its a good way to "reset" some parameters/elements to the system.

System volume is 65 gallons with displacement im calculating around 50 gallons total.

I'm thinking of doing 20 - 25 gallons?

Is this something you have done? good idea or bad idea?

Current params:
ALK: 7.7
CA: 420
Mg: 1380
NO3: 20
PO4: .14

ill be using Brightwells neo marine and i typically do 10% weekly.

 

[Goodair]

If your tank has a slow drain on the elements, a 10% weekly is more than enough. Unless you are trying to fix some parameter. If your stocked up, I'm not sure if big water changes are worth it over dosing though.

 

[Salted]

How does the tank look? While it could be said that your alk is a little low and your po4 is a little high neither is terrible. Stability over chasing numbers.

 

[mwil79]

I would agree with Salted. Do a small change maybe 5g to see what your alk goes up to and maybe run some GSO to drop the PO4 down a bit. However be careful with GSOas it does strip alk as well.

 

[Rjmul]

What are you trying to fix ?