Aquarium Forum - View Single Post

beaslbob · 09-30-2009, 04:29 PM

Quote:

Originally Posted by aspects

Theoretically, the higher you place the "T" the more pressure you will need to restart the overflow. If there is not enough pressure, the rather might fill the display before the overflow catches up. (not positive on this. One, but I will. Ask)

Actually I think you got it turned around. First there must be enough water in the water trap to fill the over the glass and restart the siphon. Secondly, The higher the water is up in the water trap the less vacume is required suck that water up to reestablish the siphon. Inside the tank can be either the loop you have or just a single pipe. As long as the single pipe remains underwater the tank side can reestablish the siphon with the vacume. But with that system the power our level is determined by the vertical location of "F". So that has to be much higher then the design you posted. That design uses the inner loop to determine the power out water level. And that can be used even with "F" much higher.

As I stated the main design difference is simply the location of "F"

Quote:

If built properly, the chance of something failing are slim. Thou, you are right, there is always a chance, however small it may be. This is why drilling the tank is really the only failsafe method. Though even then, if your overflow bulkhead clogs, or the piping clogs, you still run that slight risk. I guess its just a matt what you're comfortable with. I know people who have been running their PVC overflows for many years with no problems, and I have yet to run into any problems after initial set up. But other people may not be willing to chance it.

Or you crack the tank. Or the bulkhead leaks. etc etc etc.

the best you can do is to design and test it as much as possible.

power out to see of the sump floods.

power restart to see if normal operation returns.

failed overflow (siphon, blackage, etc etc) see if the display floods.

I have found out that there is usually a very narrow range where all those are met. Adding an automatic top off can screw that up also as water is added when the sump lowers. Which is fine for evaporation but can flood the display if it is from overflow failure. So I recommend some kind of drip system. Which can be a bear to adjust.

Have really enjoyed. Very enlightening. Thanks