Where does head start?

I have just installed a Phosban 150 powered by a maxi-jet 400. I have the pump about 8 inches down in the aquarium. It pumps about 6" +/- through the water column.
The last 2"-3" are above the water's surface and going through plumbing. I was a little suprised that I did not need to restrict the flow using the ball valve.
In the instructions it said, "Adjust the ball valve so that the PhosBan granules are tumbling slightly at the surface". I opened it up all the way and I get no tumbling.
I have added about 4" of PhosBan, reccomended is between 2" and 5".

So my question is does the head start right out of the pump, or does it occur at the water's surface?

Should I shorten the length of tubing between the maxi-jet and the Phosban reactor's plumbing?

 

right out the pump as far as i understand

 

The head of the pump starts as soon as water exits the pump. Head is generally calculated in a vertical run but is also related to horizontal run also.

Also it being in the DT are you putting the discharge of the reactor back in the DT or a sump? if its in the sump be careful of syphoning.

 

Also what kind of media are you running. I am running Phosban by TLF in mt nextreef reactor and do not have but about 3" in it. Not sure on your tank size or what 4" in your reactor equals but In the directions it states that 50grams for 50 gals for marine. If you use at higher than recommended amounts it can effect your alk. You probably already knew that but felt I needed to point it out.

 

Discharge is back into the DT, no sump yet. Big plans, little time kinda thing.

The 4" is probably between 300g-350g and it's just your basic GFO. I just hooked it up last night. I will start checking the Alk levels.
I have read about this before, but it was in the back of my mind until you mentioned it...thanks.

Just re-read the directions looking for g/gal suggestion and it does not list that, but does say 200g max or 5" of media height.
I missed the weight restriction the first time through. I had found the 2"-5" level recommendation listed somewhere else and decided to go a little over half.

I guess I should scoop out about 100g?

This is on a 110.

 

Is it plumbed correctly with the flow going in through the center and out the side so it flows bottom up and lifts the media?

Also start out with 1/2 or less the recommended dosage so you don't bleach your corals! I use maybe 3" max in a 100G system and thats after it was acclimated at 1/2 that amount. More is not better.

 

Head starts at the water surface. There is suction head and there is discharge head. The end result is net. If you had a pump 20 feet down in a tank, and it had a cut off of twenty feet, the pump would be able to pump 20 feet above the tank. 20 feet of head in the tank does not just disappear.

Horizontal runs have nothing to do with head. It only adds to resistance.

However, 2" of head is only .08 psi. You are losing your flow pushing through 4" of media.

 

Sorry for the confusion but this is what I was referring too.

Friction Head: This is also called pressure drop. When fluid flows through any system component,

friction results. This causes a loss in pressure. Components causing friction include boilers, chillers,

piping, heat exchangers, coils, valves, and fittings. The pump must overcome this friction. Friction

head is usually expressed in units called "feet of head." A foot of friction head is equal to lifting the

fluid one foot of static height.

 

^^^ yes, and to make things convenient, friction is usually expressed in terms we can relate to such as feet of head. So two 90 degree elbows of resistance to flow equals 1 foot of head. Head pressure itself is referring to how much the fluid is lifted or it's vertical run it must overcome.

 

I think you and I are actually talking about the same thing and looking at it the same way. I did find a good artical from aquarium pros that may be benifical to others
heres the link.

Pump head pressure explained.