07-24-2009, 10:00 AM
Join Date: Jun 2006
Location: Washougal, Washington
iTrader Positive Rating: 100%
| | Re: Easy DIY automatic water change system for less then $50
Originally Posted by addo
One risk with using big pipes is that the water velocity in the siphon part will be slow enough for air to accumulate over time and break the siphon. If you look at the design of overflow boxes used on saltwater tanks they usually have two or tree smaller pipes that carries the water through the siphon fast enough for tiny bubbles to be swept out of the bend.
That is why the suggestion for the barb at the top of the loop, these are only flowing the waste water, a few drips a minute, so the flow will never be enough to stop air from accumulating.