water change advice

[roggy23]

does it make a difference when u do a water change in thi s scenario----
60 gal tank and you change 20 gallons out at one time then add 20 gallons back in
or
60 gal tank and you change 5 gallons out and add back 5 gallons 4 times = 20 gal?
is the 20 gallon water change at 1 time considered a better water change or the same as dumping in and taking out 5 gallons at a time?
i hope u guys understand what im saying:nervous:

 

[alison]

:happyfish It depends what your intent is. 20 gallon water changes on a 60 gal tank is FAR too much! Maybe doing that if you have an emergency, but not once monthly. Your suppost to do 10% water changes 2 times a month or 20% monthly. If you do know what your doing, and you do have an emergency or just asking, then taking 20 gallons out is far better than doing the other in 5 gallon incriments. Be careful you don't go through a mini cycle. They say on a 60 gal. that you can only take out 30 gal. max to not go through a cycle. Good luck

 

[nm reef]

My first question is "why are you doing a 20 gal water change on a 60 gal system?"
Most hobbyists try to do a small percentage 5%-10% water change monthly. Primarily to remove some of the old water and to replenish trace elements. Personally I would avoid water changes over 10% of the systems volume. But...to address your question I think it would be better to remove all the old water then replace it with new water...remove 20 then replace 20. Mainly because if you remove 5 then add 5...the next time you remove 5 you will be removing some of the first 5 you added back which would possibly dilute your intended water change...some but not by much.