Water Change FaQ

I'd be very surprised to find anyone doing this.
It would be a lot of trouble, even to do it automatically because of the equipment, which would also make it one more thing that could go wrong.


Changing 10% every 1-2 months is really very simple. For the typical reef aquarium, doing more than that is wasted effort, salt and water.
More is not better.

The hobby used to have to change water for two reasons:
1) to reduce pollution. These days we have the knowledge of how to enable good biofiltration where Ammonia, Nitrites and Nitrates are kept low without having to do anything special.
2) to add Alk, Ca, Mg and trace elements. These days we know the inexpensive household ingredients which add Alk, Ca and Mg to keep those extremely important levels within range. The trace elements can be replenished via the 10% monthly water change.

Sorry if this goes beyond what you were asking, but it comes up often enough among newer hobbyists that for anyone reading this, it might be educational.

BTW, if you look here, Hawaii Natural Energy Labs you will see that several companies including Ocean Rider Seahorses, on the other side of the island use natural seawater pumped in to do water changes like what you are investigating. That brings up another problem with a hobbyist DIY 1% water change contraption:
How to keep the salt water fresh?
I once used some month old saltwater to do a water change and killed everything in the tank. It was clean saltwater but had been in a closed container which caused it to go foul. If I had taken time to agitate it for a day, maybe it wouldn't have killed everything, but I chose to stay on the safe side from then on, using only freshly made saltwater. Oh and btw I don't waste my time aerating it or heating it. Just mix it up and pour it in. It aerates enough as it pours in and the slight temperature difference is nothing. You oughta see what temperature inclines and declines fish and coral handle in the ocean. It might surprise you.