02-24-2011, 05:09 PM
Join Date: Jun 2009
Location: Tiffin, OH
| | Re: Automatic water change system design DIY
i have been running a very similar setup to yours in my tank. i made my drain out of 1/2" pvc however as to keep it small and ran 1/4" line to the tank to drip in. i figured the 1/2" will flow 4x as much water as the 1/4" can supply. my pickup for the drain though, i ran straight down towards the bottom of the tank which i may change to your up pipe design. the waste water is awesome for watering flowers and gardens.
a word of caution however, once you get enough air in the top of the drain loop that it shuts off the continuous flow to your vented side of the drain and then instead of the drain being the limiting factor of how high your water level is in your tank, the glass height takes over. but dont worry the water level will not go higher than the top of the glass, it just kinda trickles down the side of the tank then. if you have enough dissolved O2 or CO2 in your water to collect inside the drain it could do that. i had my setup for little over a year too and it finally did just that a few days ago. idk if having the pickup pointed up will help prevent that problem or not.