eshopps overflow box help

im getting a eshopps overflow box pf-800 for my 65g tank with a 20 gallon sump...what would be the best return pump for a set up like this

 

I would say you would want something that will push between 200 and 400 GPH at 4' TDH.


Next you would have to determine if you want an in-sump or external return pump.

An eheim can be used both internally and externally. they are electrically efficient, quiet and long lasting.

Remember you need to get a pump rated at the head height you will be using (most tanks are about 4' TDH for their return pumps if a sump is involved.

 

i thought the return pump gph flow had to be more then the overflow box?

 

The rating itself may be higher GPH than the overflow box but I can assure you that you do not want the pump to be feeding the overflow with more water than it can return - you will have either Niagra Falls-like loud rushing water or possibly a tank overflow and subsequent pump burnout.

You can certainly purchase any sized pump - you would just need to control it with a ball or gate valve to ensure your overflow box can handle the flow. If your overflow box can handle 500 GPH, then a pump running 400 GPH is ideal as you have some buffer and can run the pump wide open.

In any event I would recommend spending a few dollars on installing a ball or gate valve to control the flow on your pump. You never know when you might need or want to fine-tune or control it.

But do remember that it's the overflow box that is going to have to keep up with the pump - if the pump stops the overflow stops.

 

yea my overflow box is rated a 800 gph so i was lookin at a 500- 650

 

M-Ocean Man is right, you want your overflow box to have a higher flow capacity than the return pump and you definitely want to install a valve to adjust flow if you need to. Always install the valve after the return pump and never in the drain from the overflow.

You'll want something with a higher flow than 200gph, as the overflow box's u-tube is known to collect bubbles in it if the flow is too low, ultimately resulting in siphon failure and a flood. 300+ seems to be a number most would agree is enough to push bubbles through. In your case I'd probably shoot for closer to your 500gph that you mentioned.

I’ve been running a QuietOne pump and am very happy with it.

And if you haven't gotten the overflow box yet, look in to a PF-1000 and run it as a Herbie setup. I converted from a PF-300 to a PF-1000 and absolutely love it. More info here http://www.youtube.com/watch?v=6Pv3u0Sa1tk&feature=player_embedded

 

just as long as you are in the neighborhood of 400GPH @ 4' TDH! That is the most important thing to remember. The pump flow rating you see is always for 0' TDH on the box

 

Question about standpipes in PF-1000

I have the PF-1000 with 2 u-tubes. I thought the idea was that water only drains when the level inside the B-side of the overflow gets higher than the height of the standpipe, but this does not seem to be the case. The water is draining at the bottom of the standpipe.

It seems like the standpipes do not provide a watertight seal when sitting in the bulkhead opening inside the B side of the overflow box. So when the pump is stopped, all the water drains out of the B side and I lose siphon. Did I assemble it incorrectly?

 

I have the same unit. Do you have both U tubes so they are in the center chamber of the back section? If so the water will stay in this chamber regardless of the level in the 2 discharge chambers.

 

Yes. the U-tubes are in the center chamber of the back section. The water does stay in this chamber, but when I unplugged the return pump on purpose to test the system, I lost siphon. Even though the outside section still is full in the middle there is no water on the inside section. I think it is because the water continued to drain from the A-side until it emptied the box inside the tank.

So my theory is the standpipes I have either are too narrow so that the water is escaping at the bottom instead of draining at the top of the standpipe or maybe I didn't assemble it correctly. My LFS threw in the overflow box with the sump/refugium I bought, so I guess it's possible the standpipes are not the ones that normally come with the overflow box.