Gravity versus Feed Pump Skimmer Debate

[aquavista99]

Is it more wise to use a feed pump vs. gravity feed?  I have never used an external skimmer before and I am just wanting to weigh options before this thing arrives.

I think my EuroReef contact said you will get better results with a feed pump. It would be cheaper to use gravity feed, but I think you have more options to better control how much flow goes into your skimmer with  the first option (without resctricting the flow from your aquarium to your sump).

[Baggerhog]

I think my EuroReef contact said you will get better results with a feed pump. It would be cheaper to use gravity feed, but I think you have more options to better control how much flow goes into your skimmer with  the first option (without resctricting the flow from your aquarium to your sump).

Direct feeding your skimmer is the best way to ensure your skimmer is getting the dirtiest water. This can be controlled with a T-fitting and a gate valve. If you contact any skimmer that does not require a pressure fed then the direct feed is the way to go. If I could have worked this out to make me happy I would have direct feed my skimmer.

[bigfalcon36]

Andy, so you're refering to hook one drain up to the skimmer's water input, correct?

[Baggerhog]

Yes but most skimmers like the one you have probably would not perform well with that much flow which is why I suggested the t and then a gate valve or a high quality ball valve.

[aquavista99]

Direct feeding your skimmer is the best way to ensure your skimmer is getting the dirtiest water. This can be controlled with a T-fitting and a gate valve. If you contact any skimmer that does not require a pressure fed then the direct feed is the way to go. If I could have worked this out to make me happy I would have direct feed my skimmer.

You should see where I place my Mag 7 feed pump  (hint: it is placed in the area where both overflows drain into the sump at the same time). I also use a ball valve on the feed pump and  use a gate valve on my skimmer as well. Euroreef recommends a feed pump for best results but either way should be fine in my opinion.

[aquavista99]

Is it more wise to use a feed pump vs. gravity feed?  I have never used an external skimmer before and I am just wanting to weigh options before this thing arrives.

I prefer a feed pump but I know others who prefer gravity feed. You may want to send the US rep for Deltec an email  and see if they have a preference. If you use a feed pump, as Andy pointed out with gravity feed, make sure you place the pump in the area of the sump that contains your tank's dirtiest water (the drainage output from your tank to the sump).

[Viggen]

When you turn off your pumps on your tank you see a layer of stuff develop on the h20.  That layer of stuff on the h20 in the tank is what needs to be fed into the skimmer (for best results).  Usually when a feed pump is used it's hard to get the top layer of dirty h20 into the skimmer which is why a direct gravity feed is usually better.  Usually that layer of stuff will just fall into some place in the sump & just stay there & not be processed.  The bad thing about gravity feeding is it can be difficult to eliminate any bubbles that were sucked down the drain, they should be eliminated!!

I do think it's interesting that none of the cone skimmers I have seen are RC skimmer...... I wonder why 

[aquavista99]

When you turn off your pumps on your tank you see a layer of stuff develop on the h20.  That layer of stuff on the h20 in the tank is what needs to be fed into the skimmer (for best results). 

If you have built-in overflows, the top layer you are talking about (IE, the surface water) is what should end up in your sump. Whether you decide to capture this water via direct feed to the skimmer or placing a feed pump directly under the output in the sump should give you the same results.

[JSLeedy]

If you have built-in overflows, the top layer you are talking about (IE, the surface water) is what should end up in your sump. Whether you decide to capture this water via direct feed to the skimmer or placing a feed pump directly under the output in the sump should give you the same results.

I would think the water crashing into your sump would break the particles up and any that weren't sucked into the pump to be skimmed would return back into your system.  If it was feed directly into the skimmer then it would get skimmed before going into your system.  Both ways work but direct feed into the skimmer has to be better.  Just my thoughts.

[aquavista99]

I would think the water crashing into your sump would break the particles up and any that weren't sucked into the pump to be skimmed would return back into your system.  If it was feed directly into the skimmer then it would get skimmed before going into your system.  Both ways work but direct feed into the skimmer has to be better.  Just my thoughts.

I think the type of skimmer you operate and the design of your system will also play a significant role in how to get your skimmer to perform its best. For my system, if I ran direct feed from one corner overflow, then at least 50% of the dirty water would bypass the skimmer on every cycle from the other corner overflow. However, I think you would miss a lot of dirty water with a feed pump as well, which is why I also filter with macro (cheato) algae.

I have to clean my skimmer at least two to three times a week and I have a very light fish load. I would not want to clean my skimmer more than three times a week so I don't think I would see dramatic changes either way on my skimmer. I am curious why EuroReef recommends the feed pump method over direct feed since a lot of people seem to prefer the direct feed method. 

I appreciate all the feedback on this topic and I am sure Travis has something to think about as well since his new Deltec skimmer will arrive soon.

Attached a few closeup pictures of my design below.

feed pump goes here



dark, nasty skimmate pic

[bigfalcon36]

That last pic makes me want to go drink some coffee.

[Baggerhog]

I think the type of skimmer you operate and the design of your system will also play a significant role in how to get your skimmer to perform its best. For my system, if I ran direct feed from one corner overflow, then at least 50% of the dirty water would bypass the skimmer on every cycle from the other corner overflow. However, I think you would miss a lot of dirty water with a feed pump as well, which is why I also filter with macro (cheato) algae.

Tim you are missing the point of how much your skimmer is taking in through a feed pump. Even with your feed pump your skimmer is missing more than 50% of the water that is coming from your drain lines. I am sure your are getting about 1200 gph from your drains or more and I am sure you are not feeding your skimmer 600 gph. If so you are reducing the dwell time considerably. As far as the feeding with a drain line you are capturing the dirtiest water. The feed pump is not feeding directly off the bottom glass of the sump. This will allow a build up of desitrus to settle over time. If you direct feed you will capture more of the desitrus. The feed pump will not remove all of this. The direct feed will remove more by feeding more of it to your skimmer to be skimmed out. Just my .02 cents. I have spent a fair amount of time talking to a well known skimmer builder and he comfirms that direct feeding will get the dirtiest water. He did say that the challenge is to keep air out of the drain lines which will change the skimmers performance.

[aquavista99]

Tim you are missing the point of how much your skimmer is taking in through a feed pump. Even with your feed pump your skimmer is missing more than 50% of the water that is coming from your drain lines. I am sure your are getting about 1200 gph from your drains or more and I am sure you are not feeding your skimmer 600 gph. If so you are reducing the dwell time considerably. As far as the feeding with a drain line you are capturing the dirtiest water. The feed pump is not feeding directly off the bottom glass of the sump. This will allow a build up of desitrus to settle over time. If you direct feed you will capture more of the desitrus. The feed pump will not remove all of this. The direct feed will remove more by feeding more of it to your skimmer to be skimmed out. Just my .02 cents. I have spent a fair amount of time talking to a well known skimmer builder and he comfirms that direct feeding will get the dirtiest water. He did say that the challenge is to keep air out of the drain lines which will change the skimmers performance.

Andy, I appreciate your input, but I am going  to stick with what EuroReef recommends since I already have super clean water and very colorful corals. I can't imagine cleaning my skimmer more than I do now. The ER RC 500 has exceeded my expectations and pulls out unbelievable amounts of dark skimmate on a daily basis. I think the difference between direct feed and using a feed pump, on my system (emphasis added), is like comparing apples and oranges. If GEO tells you to direct feed, then I would follow his recommendation if I had a GEO skimmer. Euroreef recommends otherwise.

[Baggerhog]

I was not refering to Geo, I was referring to Spazz and the Volcano skimmers. I did talk to George (Geo) and he also said that Direct feed is the dirtiest water. Spazz said when I was looking at purchasing a custom built skimmer that direct feeding will produce the best results on skimmers that require a feed pump or to be feed seperate like a recirc skimmer. I am sure your skimmer is oversized but for the rest of the people reading this thread I was just trying to share the knowledge that was shared with me. I recieved some great input from both builders regarding dwell time and direct feeding. If someone has a skimmer that is maxed or close to max for their system direct feeding will allow it to run in the most efficient manner it can. Not everyone has a skimmer that is oversized for their system. I was providing input for them as well.

[aquavista99]

I was not refering to Geo, I was referring to Spazz and the Volcano skimmers. I did talk to George (Geo) and he also said that Direct feed is the dirtiest water. Spazz said when I was looking at purchasing a custom built skimmer that direct feeding will produce the best results on skimmers that require a feed pump or to be feed seperate like a recirc skimmer. I am sure your skimmer is oversized but for the rest of the people reading this thread I was just trying to share the knowledge that was shared with me. I recieved some great input from both builders regarding dwell time and direct feeding. If someone has a skimmer that is maxed or close to max for their system direct feeding will allow it to run in the most efficient manner it can. Not everyone has a skimmer that is oversized for their system. I was providing input for them as well.

The Volcano and your Geo Skimmer is basically the same needle wheel design powered by one large pump. Whereas the Deltec, H&S and EuroReef needle wheel skimmers generally use multiple recirculating pumps. My point, addressed to a larger audience as well, is that each skimmer design (beckett, spray induction, needle wheel, down draft or venturi) and sump system is different and to assume you will get the very best results by using one approach over another in all situations may not be the case. Fortunately, there are only two ways to hook up a skimmer: water is either supplied to the skimmer by a separate feed pump or direct feed. Perhaps the direct feed method does not work as well when applied to recirculating skimmers that use with multiple recirculating pumps?  Maybe the best way to go is for each individual user to try both methods and see which one produces the best results 

[Viggen]

I do not see how if it's a huge skimmer with 20 dart NW pumps or a small skimmer powered by a single sicce 2500 pump that it matters.  Dirty water is.... dirty water!  Feed a skimmer water that has more crap in it & I would think no matter how the skimmer is designed (1 pump, 2 pumps, 10 pumps) it would pull more stuff out. 

Maybe I should shoot Jeff over at ER a email/PM to see what he has to say ....   

[JSLeedy]

Bagger and Viggen your logic seems sound to me as well.  It simple doesn't seem possible for a pump to work as well as a direct feed.  Scientifically it doesn't make sense for a pump to work better or even as well.  In the long run does it really matter if you are skimming a sufficient amount for your tank? Like you said Andy it really only makes a differance if you are at the max load for your skimmer. Or you simple want to say yours is the best.

[aquavista99]

I do not see how if it's a huge skimmer with 20 dart NW pumps or a small skimmer powered by a single sicce 2500 pump that it matters.  Dirty water is.... dirty water!  Feed a skimmer water that has more crap in it & I would think no matter how the skimmer is designed (1 pump, 2 pumps, 10 pumps) it would pull more stuff out. 

Maybe I should shoot Jeff over at ER a email/PM to see what he has to say ....   

They recommend using a feed pump with Euroreef recirculating skimmers. I discussed the issue with several ER  people (Chip & Jeff) when I first purchased my skimmer and when I ordered a replacement part last Fall. ER is a small, family business. You are right, dirty water is dirty water, whether you get it from direct feed or can capture it in a controlled area of your sump and feed it back to your skimmer. It is the same dirty, raw water (so long as you can capture it in a controlled area of your sump). I suspect if you have excessive air issues in your drainage pipes, direct feed would decrease skimmer performance. Or perhaps it has something to do with using multiple recirculating pumps and being better able to control flow (without excessive air) to the skimmer from a feed pump. 

Once my system is up and running, I will post pictures of a glass of water collected from my drainage pipe before it is discharged into the sump and will  post a picture of a glass of the same discharged water that is captured  from the controlled area of my sump where the dirtiest water is collected.

Irrespective of what EuroReef, Spazz or Geo or others think, if one approach gives you better results on your skimmer than the other, then go with the method that gives you the best results.

[JSLeedy]

Or you simple want to say yours is the best.

I wasn't implying you are like that.  I don't know you.  You do have to admit there are people who want to tell everyone they have the best stuff and why theirs is better.  I have to admit it is curious why you felt the need to respond to that statement specificly.

Irrespective of what EuroReef, Spazz or Geo or others think, if one approach gives you better results on your skimmer than the other, then go with the method that gives you the best results.

I think we can all agree with that.

[aquavista99]

Or you simple want to say yours is the best.

I never said one method is better than the other method or that my design is the best. Just because I decided to go with what Chip and Jeff at Euroreef recommended for its recirculating skimmers does not mean it is the best option for you or anyone else.

[MechanicalEngineer]

This thread was split from the original thread of Tim's 300g tank to preserve the original thread and to keep a good debate alive.

[JSLeedy]

You love to split and move threads around don't you.   I have to admit I don't really understand.  Everyone that was following the thread was used to looking at it under one link I don't get the point of moving it.  It still pertains to his tank build.  I personally find it difficult to track when discussions get moved.

[Viggen]

Looks like we need another thread so we can discuss why the gravity vs feed pump thread was seperated from Tim's thread   LOL

Seriuously though......  from Jeff Macare himself

"Not a fan of direct feed as there is no way to insure consistent pressure thus consistent performance. Direct feed is best."

Which is why it isn't a good idea for some & a good idea for others.  If you cannot ensure the air bubbles are elimiated from entering the skimmer plus have consistant pressure then using a pump is best & many time easier to!!!  If those 2 issuescan be solved then go the gravity fed route.

I do plan on using my ER RC-500 (that is unless I buy a different skimmer.... hmmmm) with a direct feed from my tank.  Hopefully it will not be to difficult to eliminate those variables

[bigfalcon36]

I plan on direct feeding my skimmer...when ever it gets here...unless Deltec says otherwise.  how do you plumb the overflow/piping to the skimmer to ensure pressure and a constant feed.  Also, if a skimmer operates the most efficient between 575 and 600 gph, how do I know that I am getting between 575 and 600 gph?

Christ, now I have to e-mail Deltec...thanks guys.

[aquavista99]

Looks like we need another thread so we can discuss why the gravity vs feed pump thread was seperated from Tim's thread   LOL

Seriuously though......  from Jeff Macare himself

"Not a fan of direct feed as there is no way to insure consistent pressure thus consistent performance. Direct feed is best."

Which is why it isn't a good idea for some & a good idea for others.  If you cannot ensure the air bubbles are elimiated from entering the skimmer plus have consistant pressure then using a pump is best & many time easier to!!!  If those 2 issues can be solved then go the gravity fed route.

I do plan on using my ER RC-500 (that is unless I buy a different skimmer.... hmmmm) with a direct feed from my tank.  Hopefully it will not be to difficult to eliminate those variables

I am glad this debate was removed from my new tank build thread but I always appreciate a good debate, whether my views go against the grain or are accepted by the majority. It doesn't bother me if everyone says I am wrong. The end result is that people who see my reef in person rave about how super clean my water is, etc. However, what works best for my system may not work best for the next person, which is why I appreciate the feedback from people who have experienced better results with the direct feed method of skimming.

The gravity vs. feed pump issue came up on my new tank build thread when Travis asked a question about whether I plan to direct feed my skimmer or use a feed pump. Since we both have the same type of skimmer with the same recirculating pumps, I figured I would share the recommendation Chip and Jeff gave me from ER. No matter which option Travis selects for his new Deltec skimmer, I am sure the end result will be very positive.