Who has an intake bay? How do you maintain optimal skimming action?

[combatwombat]

I'm excavating tomorrow. Always planned to use a skimmer box, but then had the bright idea to make things more complicated at the last second and try to design an intake bay.

If I understand how a skimmer works, then the weir door kind of self-levels as the pond level rises and falls so that optimal skimming happens without any intervention. But all the intake bays I have seen have a fixed height opening, usually created by some stones. If your pond level rises, skimming won't work as well because it will be pulling too thick of an area of water.

Is that just an accepted limitation or are there some creative ways to overcome that? Maybe the effect is small enough that it doesn't really matter. I don't know!

Anyone want to educate me?

P.S. I spent about 20 min. on the phone with Trevor, a really helpful guy in the tech dept. at Aquascape yesterday, and he walked me through all the details of designing a properly sized intake bay (I forgot to ask him about pond level fluctuation...). There's not a lot of content online about the real nuts and bolts (and calculations!) of designing these things, so if you all would find it helpful, I can take some time to type up my notes from that call and share it here.

 

[Mmathis]

Following. I’m in the same boat.

 

[combatwombat]

Following. I’m in the same boat.

Hopefully some folks here who have them will chime in, Probably too late for me, though. I think I'm going to go the skimmer route and plan my dig in a way that will allow conversion to intake bay in the future if I want to do it.

This is my first pond and I'm pretty anxious about the dig tomorrow, so I'll come back with a write up of the intake bay construction steps after I settle down from that.

I used to do construction management and we dug football field sized holes in the ground, and I never thought twice about it. Now I'm putting a little one in my back yard and I can't stop agonizing over it!

 

[bagsmom]

How big is your pond going to be? Mark Wilson -- The Pond Advisor -- has some good youtube videos explaining how to do an intake bay for smaller garden ponds. I'm doing one for my pond, too, but I'm on hold till I can afford rocks. Good luck!

 

[Lisak1]

I think skimming will happen even if the water in both pond and bay is at the same level. Most intake bays that I've seen are built so the opening to the pond is narrowed, which would keep debris contained. It would create kind of a swirling effect.

Please note - I said "I think"! I've never done it, however... we have a negative edge pond that, when we get enough rain, will fill up to the level of the pond. I've watched the motion of the water, and it's still pulling toward the pump, and debris is still skimming. Plus you have the waterfall creating movement from the other direction. I've observed ours on a number of occasions because we toy with the idea of rebuilding our rain exchange as an intake bay... but I haven't gone loony enough just yet!

 

[bfull1478]

This is a really good question. I have battled this the whole time I have had a pond. Over 10 years. In my experience the door flap needs to up enough to create water surface tension. I have needed to use bubble wrap with a rubber band to keep the flap up higher than it would be otherwise. You can see for your self that when hold the flap up and allow the water to really start suck in debris on the surface starts heading for the skimmer. A lot of it has to do with how strong your pump is to suck the water enough to create the water tension. I am curious what others have done as well.

 

[combatwombat]

How big is your pond going to be? Mark Wilson -- The Pond Advisor -- has some good youtube videos explaining how to do an intake bay for smaller garden ponds. I'm doing one for my pond, too, but I'm on hold till I can afford rocks. Good luck!

About 20x40, freeform shape. I did watch Mark's intake bay video. It was helpful, but didn't address water level fluctuation.

Thinking about it more, if you set an auto fill system and an overflow outlet where you want them, you can probably keep things within a pretty small tolerance.

I think skimming will happen even if the water in both pond and bay is at the same level. Most intake bays that I've seen are built so the opening to the pond is narrowed, which would keep debris contained. It would create kind of a swirling effect.

Yep, it will. What I'm referring to is how high (or low) that level is to the barrier you place at the opening to the intake bay, due to water level fluctuation which would affect the power of the skim that you get, which might really mess with performance on a larger pond.

This is a really good question. I have battled this the whole time I have had a pond. Over 10 years. In my experience the door flap needs to up enough to create water surface tension. I have needed to use bubble wrap with a rubber band to keep the flap up higher than it would be otherwise. You can see for your self that when hold the flap up and allow the water to really start suck in debris on the surface starts heading for the skimmer. A lot of it has to do with how strong your pump is to suck the water enough to create the water tension. I am curious what others have done as well.

Interesting. So you've experienced the same "problem" with a skimmer? This is all theoretical for me. I've never used a skimmer or an intake bay. Just done too much research and this was the big question that came up for me.

Trying to think about how you might create a door for an intake bay to get the same effect. Would start looking unnatural, though, which is the whole point, I think, of an intake bay.