Series of questions related to water change stations

[Myka]

^ Very good advice.

I have a maintenance company and find that most reef tanks do well with 10% per week. For those that tend to overfeed their fish or don't use skimmers, I do up to 20% weekly.

For water change stations I like the saltwater mixing tub to be either the same size as the water changes or twice the size. So I can either fill it up every second week, or every week after the water change. Mixed saltwater is very stable, and really it can be as large as your heart's content. Once it is fully mixed and dissolved (a few hours) you can turn the pump off and restart the pump a few hours before your water change. using a smaller saltwater tub allows you to also turn off the heater in between uses.

For the RO/DI tub, I like it to be at least 2x the volume of the water changes, but preferably closer to 5x. You don't want the RO tub to be too big though because RO/DI will absorb "stuff" out of the air and your 0 ppm TDS RO/DI doesn't remain at 0 ppm forever. If I need to do a large water change then I can add salt to the RO/DI tub as well as the saltwater tub and have lots of saltwater.

Also, I like to put a tee in the RO/DI product water line and have one go to the RO/DI tub and one to the saltwater mixing tub. This way you can fill either one up independently of the other, and you don't have to worry about transferring water from the RO/DI tub to the saltwater tub.

Since we're at the storage tank size stage...if you're going to use an auto top off (highly recommended) don't make it any larger than about 10% of the tank's entire volume. This way if there is a problem with the auto top off sticking on (yes it does happen) then it doesn't have enough volume to crash your tank by diluting the salinity, and if you're smart about sump design, there will even be enough soom in the sump to hold that extra 10% and not get your floor wet.

Some people direct plumb their ATO to the RO/DI and some people put the ATO right into their giant tub of RO/DI. Either action is laziness and playing with fire imo, and I can easily think of at least half a dozen people on these forums that have crashed their tank this way.

[shiftline]

Garage can work if you automate it. If you do small daily ones you won't have to worry about pre heating the water.