Water changes

[curiousphil]

Do that drain and then add new saltwater, or add new water and then drain?

 

[curiousphil]

Do that drain and then add new saltwater, or add new water and then drain?

I notmally drain first and then addy water but I find that its harder  to control the final water level that way.

 

[theyangman]

Adding first is a waste of good clean water. You are diluting the dirty tank water, and then draining some of it back out again. It makes no sense. Where as you could remove only dirty water, and then add only clean water not wasting anything technically.

ie:

Lets say you have a 100 gallon tank and you do a 20% water change.

scenario 1. you would be adding 20% water increasing the volume to 120 gallons and then taking out 20 gallons. But in this instance 20% clean water has mixed in with your "dirty" tank water and you are siphoning 20 gallons (16.7%) but some of which will be your clean water. You are hence then only diluting it by 16.7%

Scenario 2: You siphon out 20% and then add that same volume back in effectively diluting your "dirty" water by a full 20% in this case.

So you are losing 3.3% overall in your water changes, and not cleaning your water by that same percentage vs the other method.

 

[Pistol]

I drain via vacuum substrate turkey baster the rocks then add.

 

[MrHermit85]

I also remove my water first. I have two barrels both exactly the same and both marked at the same level (a little extra to account for the amount the pump can't remove) i then fill the dirty water barrel till the line and once done pump water from the freshly mixed barrel. I have never had a problem with my water level afterwards. And I use the leftover the pump can't get out to flush the reactors out with.

 

[draper]

use a vacuum to clean gravel removing water at the same time.  then add your new water.  15% every two weeks.