Originally Posted by
wattsupdoc
http:///forum/post/2802325
There are quite a few threads on here with DIY PVC OF's. They have been around for quite some time. Many use them and reportedly they work pretty well. You CAN and MANY DO use ball valves on the drains, however this would be with a built in OF, coast to coast, baffles whatever, but not a HOB or DIY PVC. It's a different concept that has been around for a long time. It works, and some use it flawlessly, but IMO a back up is beneficial, google "Herbie Style Drain". for more on these things. There is no point in trying to control the drain, let what the pump delivers be the control.
To roughly determine how much room to leave in a sump/fuge find the estimated backwash. I usually allow 2 in of the DT's height for backwash. To fing this then, HxWxL /.231=gallons
so plug in your measurements using 2 as the height. Now this is youir estimated backwash, leave at least enough room in the sump to allow for this. However, you dont have to just leave this amount. If youer backwash calculates to say 4.5 gallons, and your desired water level leaves 10 gallons, great!. It is recommended to install the sump fill it with the desired water level while running, then add a little under your estimated backwash. start up and let it circulate, adding more SW if needed to run properly. BUT don't add so much that shut down floods. Now when you have it operating just right, shut it down and be sure that it doesn't flood. If everything was done correctly, then you WONT FLOOD PERIOD.
Dont worry too much about very short (hour or less) power outages. You will usually be OK for quite a while without power. (couple hours) Unless you are very heavily loaded, or have some other scenarios that might be an issue, like exposure to heat/cold. For extended periods, you can use an inverter/battery set, a portable backup generator, or a standby generator. Either of these methods will get you through practically any emergency sceneario involving power outages.
johnyd, what is your point here? Why would you post basically suggesting to someone to utilize an inferior filtration? I spilled more water using my filstar canister filter than I have ever spilled using my sump/fuge.
here's my question on calculating backwash. if i use 2" for my height and my tank is 90gal. my tank measurements would equal 2x18x48/.231. using this equation i'd have 399gal of backwash. i have to be pluggin these numbers in wrong somehow. are u supposed to multiply HxWxL and divide by .231????
And the way to go.
