The really really simple water change method

[DanConnor]

This might seem obvious, but I lately seem to have noticed a lot of very expensive and complex ways of replacing exact amounts of old water with new, and I hope people aren't overlooking this.

All it requires is that you maintain a steady water level in your sump, and that level is high enough that you can put your bucket or drain below it. Probably wouldn't be suitable for continuous water change setups.

Anyway, see the pic.

 

[goodtimes]

I get the idea but isn't there a chance that the new water will go out with the old.

 

[DanConnor]

Same with any water change- it depends on where you pump the new water in to. Either next to the return pump back to the tank, or direct to the tank.

 

[NanaReefer]

This is interesting to me as I'm upgrading to a new 40b with a 20L sump. Am wondering what is the best way to do WC. I've never ran a tank with a sump before.

 

[larangcon]

I have a same set up, gravity fed rodi water to the sump with a micro valve for the supply drip.
Once you have the right balance of drip per second all you really have to do is maintain the water level on the rodi tank, worked for me.

 

[goodtimes]

Same with any water change- it depends on where you pump the new water in to. Either next to the return pump back to the tank, or direct to the tank.

I take the old water out before I put the new water in. But I also clean the top layer of the sand bed.

 

[Singlefin]

I have an mj1200 with a 5ft hose connected to it. Turn off my pumps. Sump fill up. Pump out 5g into an empty bucket. Pump 5g new water back into sump. Simple.

 

[vlangel]

This is interesting to me as I'm upgrading to a new 40b with a 20L sump. Am wondering what is the best way to do WC. I've never ran a tank with a sump before.

You are going to love a sump. Its great for WCs but has many other benefits which I know you know.

 

[DanConnor]

Since I had this idea, I've set up a system using it, but even simpler. The new salt water chamber is above the sump so I don't need a pump, and the waste goes directly to my sewer line. So to do a water change- just open 2 valves!

It's a 50 gallon container for an approx 250 gallon system. The new water enters right next to the return pump which takes it upstairs to the display. A small amount of fresh probably will end up in the drain, but I think its a minor drawback.

I set my ATO level a hair lower than the drain level, so if I were to forget to shut the valves it wouldn't keep running in RO water.