<a href=showthread.php?s=&postid=6800593#post6800593 target=_blank>Originally posted</a> by jnarowe
Shawn,
It's hard for me to follow how you are setting up your flow but I want to give you my 2 cents anyway. If you look at my thread you will find pics of my manifold. Originally I wasn't going to use this method but after reviewing pros & cons, I decided to mount it slightly above the water line of the tank as a safety measure, and use several valves to direct flow.
Because I built the manifold and installed it up high, I went with flexible PVC to cut down on back pressure associated with angles. From this manifold I can feed the tank, ref, and any other equipment like reactors, frag tank etc. Any of the individual destinations can be isolated by closing a valve and using one strong pump rather than multiple pumps really helps on electrical draw.
All "destinations" drain by gravity feed. I have the ref draining into the display (it's mounted above) and all roads lead to the sump of course. You can do the same by feeding your ref, then draining into the frag, and then into the display. The obvious issue is access to the frag tank. The way I would approach that is to "T" or use separate drains from the ref, with one going to the tank and one to the frag. The frag can drain into the sump. With no sand in the ref, you can push a little extra flow as well.
Gravity is your friend if used properly because it will interupt the flow should there be a pump failure or electrical outage. Just use stand pipes to drain each area rather than just a BH. So then you have the question of flow in the frag tank: here you can have your inflow from the ref at one end and a Tunze or Vortech at the other end. You have solved flow issues with much less electrical usage.
I also have an extra drain in my ref that is a straight BH mounted highest, and drains into the display but from above the waterline so that if it is being used I will see air bubbles in the display. That is a safety drain and seeing the bubbles will tell me that my main drain is clogged. And, I have another drain in the ref that goes to a 1/2" pipe mounted by the QT. This will gravity feed the QT with tank water so that when I am acclimating new arrivals, I can slowly blend in tank water (with pods of course). This is set up with a float valve on a 1/4" line. What I do is remove a few cups at a time from the QT, and allow it to refill from the tank.
Another "T" off this 1/4" feed goes to a small manifold with four 1/4" lines that are used for drip acclimation. Now you have a little more to ponder!
