Plumbing question - Gravity feeding a skimmer

[mattseattle]

eeks................

 

[Willy]

Well I dont have a pic of mine and Im too lazy to take one. BUT, I overflow feed my skimmer as well, and for flow adjustment I use a ball valve on the pump side to "bleed off" flow back into the sump. I must have the flow dialed in about right, my ASM skimmer is skimming very well.

 

[mattseattle]

i also have a valve on the outlet of the pump so i can control water flow through the skimmer. i also put one where you saw it in the picture to control flow into the skimmer. that is how i interpreted alot of the designs.

 

[Willy]

i also have a valve on the outlet of the pump so i can control water flow through the skimmer. i also put one where you saw it in the picture to control flow into the skimmer. that is how i interpreted alot of the designs.

Either should work fine. I had a gate valve on my overflow to sump plumbing b4 I did the gravity feed mod/recirc mod and the way I had it, I didnt like at all. Now, with the durso in my hang on back overflow and the skimmer being gravity fed it is dead silent. I love it this way

 

[mattseattle]

do you have any surging or gurgling in your skimmer due to the gravity fed?

oh the valve is not used to slow the flow down from the overflow but only into the skimmer. the T handles the excess overflow. i will only control the water throught the sump via the pump valve.

i will also have 2 dursos in my over flow box to stop the water fall effect.

 

[Willy]

do you have any surging or gurgling in your skimmer due to the gravity fed?

oh the valve is not used to slow the flow down from the overflow but only into the skimmer. the T handles the excess overflow. i will only control the water throught the sump via the pump valve.

i will also have 2 dursos in my over flow box to stop the water fall effect.

Very little . Once I got the hole in the durso the right size it all pretty much eqaulized

 

[Reefdaddy1]

That was a PG statement Bob a PG statement I promise!!!!

I know it was I was talking about your dog, You have to pet it right? LOL

 

[Haole]

Hey Matt,
You were saying that you’ve gone through a lot of info on different ways to gravity feed a skimmer. Could you possibly post some links of what you’ve found?

I’m currently running my skimmer by gravity feed and I’m curious to know if there may be a better way to do this than the way I’m doing it now.
From my experiences so far, and looking at your pictures, I’m wondering if by the way you have yours set up that you might run into a problem with introducing larger bubbles into your skimmer from the turbulence of the water cascading down from your tank. From what I’ve read about skimmers, and correct me if I’m wrong but, you don’t want large bubbles in the contact chamber because they’re less efficient and they disrupt the surface tension within the skimmer making it harder to create consistent foam that will eventually rise up and make its way into the collection cup. That’s why I made a little pool per say with a large Tee fitting that the water coming down from my tank enters into first to slow the turbulence and give the larger bubbles a chance to burst out of the water before heading to the skimmer. I used to run all of the water coming from my overflow through the skimmer until I learned and realized that I was running too much water through it which was just killing the contact time plus all of the turbulence. It’s a bit of a balancing act because it takes two valves to pull this off, and the flow rates do gradually change over time between cleanings of the return pump and plumbing which ultimately dictates the flow.
Here’s what it looks like...

The way you have yours set up looks much simpler and easier to regulate the flow to the skimmer, but like I previously said in my ramblings, I’m just curious about if larger bubbles will make their way into the skimmer.

 

[mattseattle]

Hey Rob - thanks for the pictures and thoughts.

All of my readings have come from the Deltec and H&S Forums on Reef Central. I've seen tons of diagrams and several photos. Yeah, you are correct on the large bubbles as you don't want those travelling into your skimmer. From what I've read you use the T and the Ball valve to help with that issue. I am also going to be using a Durso so that should also help with some of the bubbles.

How many GPH are you running through your skimmer?

I also just had a user on Reef Central comment on my set up. Everything looks perfect except for where I change from 1.5" down to the PVC going into the skimmer. I am making the transition after the ball valve way too quick. They said I won't get adequate GPH through the skimmer with that set up. So now I need to figure out how to get a 1.5" elbow under the ball valve and over to the skimmer. That should be fine trying to squeeze an extra inch or so of space.

does it hurt if you have PVC running up hill a little? I think that may cause more surging and gurgling though.

 

[mattseattle]

ok, i have to change my design a little bit.

i don't have the parts to do the change or else i would have new photos.

i think this change will work a lot better. i am going to run 1.5" PVC horizontal (just like it's in the picture) and at the elbow that is going down I am going to convert from 1.5" to 1" PVC at the elbow. From there down it will be 1" PVC all the way to the skimmer where it will change over to 1/2" and go into the skimmer. I think by reducing down to 1" first off it will give me more space to work with and second it will create a back log of water to enter the skimmer. this will help with any bubbles as well as generate enough flow to accomodate the skimmer. a 1" valve takes up a lot less space than a 1.5" as well as a T. I don't know why i didnt' think of that earlier. Now if there was only a 24 hour Home Depot.

 

[Haole]

Hey Matt,
Thanks for the info...
Like I said earlier, the return flow from the sump to the aquarium ultimately dictates what flow rate you can supply to the skimmer. My return flow is only like 150gph. (my aquarium is only 40 gallons) I can only make a guess here, but from observing the flow rate coming out of the skimmer it’s definitely less than half of the flow that is going directly into my sump... Maybe 50gph? And again from my readings about skimmer efficiency, you want to have a slow flow rate going through the skimmer to maximize the contact time. Of course this is only possible with certain skimmer designs.

I hope your changes will work out for you!
I’ll be interested to see how this works for you, so make sure to keep us posted.

 

[mattseattle]

with my set up you can actually run more flow through the sump if you wish. you control the flow through the skimmer via the ball valve. this ball valve also creates a slight back up for the skimmer to prevent gurgling and surging and to release any air bubbles. they will go up to the T and out the other side. My skimmer is rated for 210 gph so I am going to run it probably about 190 - 200 gph on my tank. We'll see how the skimmer performs and adjust from there.

Hopefully the new design will work well. I'm off to Home Depot to buy more PVC parts. I swear I'm opening up a PVC Supply place.