Equipment on outflow vs inflow

Outflow is always a good idea due to designs on the pumps on canister filters. You always want to restrict the outflow versus the inflow.

IMO as long as the heater doesn't reduce the flow much, the only drawback of being on the input would be unfiltered water flowing through it.
My Rena Smartheater is designed to attach to the input FWIW.

On UV, other than restriction, I'm not sure if there's any pros or cons as to it treating unfiltered vs. filtered water.

hm, thanks. I wasn't sure. I just wanted to make sure I covered all bases.

You usually put the heater on the outflow since you don't want a bunch of gunk accumulating in the heater. The filter provides mechanical as well as biological filtration. Better for your heater, and less time spent cleaning it, if you let the filter remove any particulate matter from the water before you run it through the heater.

i figured that the reason the manufacturers want things on the outflow is because if you block the water going into the cannister and fry it, you could blame them.

Go with a manifold, they are awesome....DC

Heh, I'm still quite a novice with PVC, so this is kind of a trial run. That manifold you made looks great DC. I think I saw a union piece at the hardware store. I was trying to plumb my hydor heater into the actual PVC, but the 1/2" NPT/NPT and 1/2" NPT/slip that I tried, weren't allowing enough room for the long nipple on those heaters. My solution was to use a small section of hose on either end and use a 1/2 NPT nipple for connecting the hose.

I'll get a picture taken as soon as I'm finished.

ringram said:

Heh, I'm still quite a novice with PVC, so this is kind of a trial run. That manifold you made looks great DC. I think I saw a union piece at the hardware store. I was trying to plumb my hydor heater into the actual PVC, but the 1/2" NPT/NPT and 1/2" NPT/slip that I tried, weren't allowing enough room for the long nipple on those heaters. My solution was to use a small section of hose on either end and use a 1/2 NPT nipple for connecting the hose.

I'll get a picture taken as soon as I'm finished.

Click to expand...

It took a few trips for me to find the right piece of pvc that would fit over the heater barbs but I did find a type with a longer neck. The manifold was quite easy to make once I had all the parts identified and tracked down; I still consider myself a pvc novice too, I do not even know what most of the pieces are called........DC

I would place your equipment on the pressure side (outflow) of the canister to ensure it doesn't leak.

If you turn the canister off, or the power goes out, the water pressure inside your equipment (external heater, co2 reactor etc) *reduces* and if your equipment didn't leak under running pressure it almost certainly won't leak with the power off.

If the equipment is on the suction side of the canister the water pressure in your equipment will *increase* when the power goes off (especially if the equipment is underneath the tank due to the siphon pressure). It is possible to have no leaks while the filter is running but when the power is off the pressure rises and you could have a leak that you didn't know about. If this happens when you are not home you could have a disaster on your hands.