Info on these auto water change units

[Aquaph8]

Can someone explain/review the auto water change units and share as much info as you can about them. They seem pretty cool but how much space is involved in keeping one of them going and how do they work?

 

[secretreefer]

Genesis Reef Systems

 

[secretreefer]

Product Review: Genesis Reef Systems – Renew – Part 1 | Reefs.com

Here's a review of the product.

 

[mfdrookie516]

My issue is that you're losing a lot of efficiency in water changes this way. On a 100g system, you can set it to do 15 1g changes, but that's nowhere near as effective (in terms of dilluting) as doing a single 15% water change. You're doing 15 1% changes. Doing 15 1% water changes is much less effective. Just seems like you'd have to waste a LOT of water to achieve the same results... so I suppose it's cost vs. labor. Either do the water changes yourself, or pay a little extra in salt and water (and ultimately resin, membranes, etc).