simple gravity fed question

[janine9620]

Okay this is probably basic stuff here, but I just can't get my mind wrapped around it. If I retro fit a BD to a 30" pond, come up and over the edge, down the elevation of the yard slightly and dig a hole and feed the pipe in there, That hole WILL fill to the pond level? Then I can extract from there and feed through my bead filter? I know when you siphon an aquarium it works that way, but thats a drastic gravity change up and over, this is gradual. It sould still work though right??? Even though the line goes higher than the pond level at one point??? I know this is prob a dumb question, but I just don't get it? :icon_smile:

 

[koikeepr]

Technically, yes. It's not the most ideal to have it go up over the pond edge because you lose some friction with regard to the pump, but as long as the pump it's feeding from is lower than the water line then that's basically gravity fed. The pump will have to pull a bit to get the water over the edge of the pond, but it is still gravity fed technically.

You don't mention what type of pump you're using: submersible or external.

I'm actually doing the very same thing myself. I just dug a 5 x 5 x 3.5 filter pit which will house a new 55 gallon skippy/bio filter, my existing pressure filter, my external pump and a sump pump (to protect my external pump in case of a flood). My retro bottom drain will feed into the barrel, as will a small skimmer I'm putting in. I will have my BD piping go over the edge of the pond as well.

You are thinking about it correctly. Not a dumb questions at all. Plumbing is actually pretty complicated, which is why plumbers go to school--we're just trying to wing it! LOL!

 

[janine9620]

I have a sequence 750 series used pump, I believe the minimal 750 series is 3200 gph, so I'm assuming that is what it is. It feeds to a Ultima2 bead filter, on the outflow I also have a Half Whiskey barrel uplow veggie filter, then back into the pond. I don't use a submersible.
Okay, so I thought by gravity fed, it meant no pump for the water to flow from the BD to the SC, (it would "just" happen) then I'll plumb the intake of the filter to the SC, avoid all the crud that has been gunking up my pump? Is that right?

 

[koikeepr]

good. glad to hear you have an external/sequence. I have a sequence 750 too. I have the 4200.

Gravity fed simply means that your pump is below water level, so that it doesn't need to pull water. The water simply flows into it by gravity and then it is able to push out the outflow. Once the pump is above water level, you start to create pressure or a "pump fed" system instead of gravity fed. The sequence can handle that if necessary, but it is not the most efficient use of the pump.

But, yes, you are thinking about it correctly.

Do you have a leaf trap/priming pot on that pump? If not, you should. Not sure if that's what you mean by "gunking" up the pump. Do you also have a check valve on it? You should have one on there before the pump.

 

[koikeepr]

perhaps this

will help you.

 

[janine9620]

I am at grade level. To wet here at times to go below by digging. I raised the pond slightly for the same reason, but the pump and the pond level are abot the same. Yes I have a basket on the pump, but fine algea gets through and I end up having to take the pup apart and clean the propeller thing. I now have some filter media i there to to catch it. I clean everyday or two. I can attach the BD to the direct line, but I wanted a place for solids to settle first.

 

[janine9620]

sorry i didn't spell ck

 

[koikeepr]

yep. we are simpatico. That's why I'm putting that 55gal bio filter in front of my pump, so that it will catch solids BEFORE it hits my pump.

Do you have a UV light on your system? That usually helps with the algae. I don't personally have any (knock on wood), thanks to my UV. Where is your filter? Do you have it after the pump? You might want to reverse it and put it before your pump, or add another one (even a small one), to catch the thicker stuff first.

 

[janine9620]

Well I finished my bottom drain! I should have taken pics, it turned out pretty good and works fabulous! It is not gravity fed, but is pumped, just couldn't get low enough for the gravity feed to work. Anyhow, I got a roof flashing boot from Home Depot, Fitted it with a 3" to 4" rubber adapter fitting, it slid up through the rubber boot, but the larger 4" end sealed the rubber against rubber. I turned it over and filled the voided area in with concrete, weighing down in the water. Trimmed off the squared edges (kinda reminds me of a fire helmet now) Placed some black rubber feet about 3/4 inch, and placed a 45 degree PVC elbow into the 3" opening (this was the only thing I had to paint black) Attached my flex hose and it was up and running. Found a tiny black stepping stool at big lots, cut a hole through it, it slides down over the fitting, resting on the ledge of the BD and provides a perfect shelf for my Water Lily. I did change up my out flow, to push water along the bottom too, towards the BD. All the gook is GONE, and my fishies love playing in the new current. The bottom liner now has this really nice emerald green/dark green pattern on it, looks rather pretty actually The only down fall, with my pond being overstocked and the much better system, My prepump basket fills fast. I dump it everyday:zap:...is that normal? Oh and one snail keeps getting sucked up, I just keep throwing him back in

 

[koikeepr]

LOL! You are very inventive. Good use of the rubber boot. I've seen people do this before as well. Nice and CHEAP! Yes, you are using the return water like I am...to push the muck toward the BD.

Your baskets should slow down once all the gunk from the bottom is picked up initially. You could just take your return outlet and try to use it like a hose and push everything toward the boot so things happen more quickly. I don't think it's abnormal in your case, especially since you don't have a skimmer. Normally, the skimmer might pick up 75-80% of stuff before it sinks to the bottom. Of course, you don't need a skimmer at all--but you can grab a net and just clean the top of your water every day. It takes just a few minutes if it's a routine.

Sounds like you're on a great track. Congrats.