Gravity Feeding a Skimmer

[jscarlata]

the plans for my 120 are progressing nicely, after reading an older thread on the calfo style overflow boxes thoroughly, i've decided to pursue a full length glass calfo. I'm ging to plumb three Durso style drains, 1inch each, 2 to the sump and the third i wanted to use to gravity feed an external skimmer. The thing is, i don't know much about all the various skimmers out there; the choices are dizzying and none of the adds or descriptions mention gravity feeding. To gravity feed do you need a specific kind of skimmer or is there just a specific way to plumb it for gravity operation. Can you guys guide me here? I dont necessarily need to know any specific brands, as so many people have different preferences, but i need to know what specs i am looking for so i size it right...any info is much appreciated

 

[Hammercoral]

Any skimmer that can be run Externally is what you are looking for.

 

[pjf]

External Recirculating Skimmer

External Recirculating Skimmer

<a href=showthread.php?s=&postid=8973622#post8973622 target=_blank>Originally posted</a> by jscarlata
I'm ging to plumb three Durso style drains, 1inch each, 2 to the sump and the third i wanted to use to gravity feed an external skimmer.

I believe that what you are looking for is an external recirculating skimmer. Your skimmer sits next to the sump. It is directly plumbed to the overflow. The overflow pipe contains a “T” to allow excess water to drain into the sump. Between the “T” and your skimmer is a valve to adjust the water flow into the skimmer. The outflow from the skimmer goes into the sump.

Your skimmer does not have a feed pump. Instead, it has a recirculation pump that takes water from the skimmer body, adds air to the water, and pumps it back into the skimmer body. Such a skimmer is very efficient.

Here is an example of an external recirculating protein skimmer:
http://www.marinedepot.com/aquarium_protein_skimmers_Euro-Reef_cs_rc_sedra.asp?CartId=

Here is an example of an in-sump recirculating protein skimmer:
http://www.marinedepot.com/aquarium...c_turboflotor_t1000_information_1.asp?CartId=

 

[UCanDoIt]

<a href=showthread.php?s=&postid=8941341#post8941341 target=_blank>Originally posted</a> by UCanDoIt
Because the H&S pumps are located slightly higher on the recirculating skimmers than non-recirculating in sump only skimmers, there's no microbubbles.

The unique wedgepipe design is very easy to adjust for type of skimmate, but of course, the quality skimmate is also a factor of how fast you pass water through the skimmer as well as how the air hose is adjusted for foaming.

You can feed this skimmer by a corrrectly rated powerhead or what works best is if you can feed directly from the tank's overflow by gravity feeding.

<a href=showthread.php?s=&postid=7303604#post7303604 target=_blank>Originally posted</a> by UCanDoIt
In response to several PMs about water level and bubble breaking level, I thought it best that I copy in a previous post that I did about the same subject. Sorry about the Deltec photo as I own both and this was readily available.

<IMG SRC="http://usera.imagecave.com/winner/DeltecBubbleBreakLevel.jpg">

<a href=showthread.php?s=&postid=7300811#post7300811 target=_blank>Originally posted</a> by UCanDoIt

I have spent many many hours talking to the my Aquarium tech (who maintains all my tanks) about plumbing and he's tried it all, made his share of mistakes, and the way he has my tank set up works great.

There are 3 controls on the skimmer:
1. Input controlled by gravity feed from overflow with ball valve "or" a feed pump with the correct rate
2. Output controlled by wedgepipe at skimmer's exhaust drain
3. Air flow controlled by air clamp

To set your skimmer correctly (as I am told):

1. first you must be sure the water flow through rate is matched to your skimmer. most of the time, for gravity feed, one would need to tailor the rate back by ball valve in control #1 as the water turnover rate on your system is usually much stronger than your skimmer can handle. if not tailored back to the correct flow through rate, there will be too much turbulance within the skimmer and performance will be greatly affected. or you can feed skimmer with a correctly rated pump or powerhead

2. next, with the water flow through rate adjusted correctly, the water level within the skimmer must be at the right level for the skimmer to perform optimally. water level should start right at the bottom edge of the bayonet connection between the collection cup and skimmer body. if the water level is too low, tailor back the outflow from the skimmer drain with the wedgepipe and it will raise the water level within the skimmer body. again, use the wedgepipe on the output, which is control #2, and be sure the drain does not terminate underwater in the sump. if the exhaust terminates underwater, the skimmer does not function well for H&S skimmers. on my setup, I have a 90 elbow that directs the water down into the sump, but the end of the pipe is about 1/2" above the sump water level. to quiet & reduce splashing, you can put a 45 elbow at the end of the drain pipe

3. tighten the air clamp for maximum foaming with control #3. on both my Deltec and H&S skimmers, it is tailored back approximately 1/4 - 1/3 which gives me the finest bubbles and good foaming head. on some skimmers, a fully open air tube could possibly be your best performance as every skimmer is different

once your skimmer is broken in and foaming, adjust wedgepipe to raise the water and bubble breaking level for wetter skimming and lower for drier skimming. HTH:rollface:

<a href=showthread.php?s=&postid=7270726#post7270726 target=_blank>Originally posted</a> by UCanDoIt
In response to question by email about details on the gravity feed. If you are going to gravity feed from the tank's overflow box, you need the pressure to be constant going to the skimmer, so the greatest waterflow should be directed straight towards the skimmer and then tailored back by a ball or gate valve. You also need a T fitting before the ball or gate valve, so all the excess surging and gurgling that goes on with overflows empties out on the side of the T into the sump. Here's a sketch that my aquarium maintenance person did for me when he setup my tank. My gravity feed in an earlier photo is setup exactly like this.
<IMG SRC="http://usera.imagecave.com/winner/GravityFeedPlumbing.jpg">
<IMG SRC="http://usera.imagecave.com/winner/GravityFeedValve.jpg">

 

[jscarlata]

Perfect...thanks a lot guys...i was actually contmplating buying a used H&S from the place i'm getting my tank and sump from, so this definatley helps a TON

 

[UCanDoIt]

You're welcome. I just forwarded a PM to you to help you calculate the right skimmer to get for your setup. Check your PM inbox when you get a chance. Christine