Head Loss

[tinmanunited]

I used the head loss calculator over at reef central and found, based on my return plumbing, that my pan world 100px-x rated at 1270gph reduced to 840gph. My total system volume is roughly 140 gallons. I do have a reeflo on a closed loop pushing out 2700gph. Question is, is the 840gph enough flow through the sump? I'm considering going with the Panworld 200ps, but it uses considerably more power 290watts compared to 130 watts. Is it worth the upgrade? Will my overflow handle the added flow. Its 20'" x 5" with the about 18" of slots.

 

[cedzaquaddiction]

I think it'd be alright to stay how you are. The closed loop will turn the water over and you don't want your flow through your sump to be too high. The more time your water spends in your sump, the more time your skimmer has to filter it. Just don't have the water going too slowly through your sump. JMO. Hopefully someone with more experience will chime in...

Best of Luck!!!

 

[grouper therapy]

CedzAquAddiction;850200 wrote: I think it'd be alright to stay how you are. The closed loop will turn the water over and you don't want your flow through your sump to be too high. The more time your water spends in your sump, the more time your skimmer has to filter it. Just don't have the water going too slowly through your sump. JMO. Hopefully someone with more experience will chime in...

Best of Luck!!!

Based on that a HOB skimmer would be rendered useless since all the water is available to it.
The skimmer will only clean the amount of water it pulls in through the pumps that feed it. The flow through the sump only affects devices or media that the entire flow of the sump goes through such as filter socks etc.

 

[tinmanunited]

Yeah, but if it's a picky skimmer it will want time to choose.

 

[cedzaquaddiction]

grouper therapy;850208 wrote: Based on that a HOB skimmer would be rendered useless since all the water is available to it.
The skimmer will only clean the amount of water it pulls in through the pumps that feed it. The flow through the sump only affects devices or media that the entire flow of the sump goes through such as filter socks etc.

Correct, but I thought we were talking about an in-sump set up here.

With an in sump setup, it's up to the flow in the tank to keep the water circulated and therefore having dirty and/or surface water going into the overflow, and therefore into the sump to be filtered, correct? I'm new to this whole sump thing, so I'm open to learning what I can. Especially by more experienced reefers like yourself. If my logic is wrong, please let me know. Just asking because I don't know 100% for sure. Just seems that if the flow in the tank didn't exist to supply random water to the overflow, there would be water in the tank that doesn't get filtered. With the flow, a much larger percentage of the water is in circulation to be filtered.

Edit:

TinManUnited;850219 wrote: Yeah, but if it's a picky skimmer it will want time to choose.

That was what I was trying to get at. May have said it wrong. Just seems that if water were rushing through the sump, the skimmer would have less chance of filtering the majority of the water passing by.

 

[grouper therapy]

I wasn't questioning the need for lots of flow in the display, I was refuting that slower flow through the sump helps the skimmer's efficiency. The skimmer is gonna process x amount of water and x amount of nutrients are gonna enter the system. The only way flow through the sump will impact a skimmer's efficiency is if it is too slow and the skimmer is " starved" for dirty water to process.

Edit:

CedzAquAddiction;850267 wrote: Correct, but I thought we were talking about an in-sump set up here.

With an in sump setup, it's up to the flow in the tank to keep the water circulated and therefore having dirty and/or surface water going into the overflow, and therefore into the sump to be filtered, correct? I'm new to this whole sump thing, so I'm open to learning what I can. Especially by more experienced reefers like yourself. If my logic is wrong, please let me know. Just asking because I don't know 100% for sure. Just seems that if the flow in the tank didn't exist to supply random water to the overflow, there would be water in the tank that doesn't get filtered. With the flow, a much larger percentage of the water is in circulation to be filtered.

Edit:

That was what I was trying to get at. May have said it wrong. Just seems that if water were rushing through the sump, the skimmer would have less chance of filtering the majority of the water passing by.

It is only gonna process what is pumped or feed in to it regardless of the velocity of the water going by. Actually the odds would be in favor of it processing dirtier water at a higher flow rate. If you can view the sump and the display tank as one system which they are that might help with the understanding.

 

[cedzaquaddiction]

grouper therapy;850287 wrote: I wasn't questioning the need for lots of flow in the display, I was refuting that slower flow through the sump helps the skimmer's efficiency. The skimmer is gonna process x amount of water and x amount of nutrients are gonna enter the system. The only way flow through the sump will impact a skimmer's efficiency is if it is too slow and the skimmer is " starved" for dirty water to process.

Edit: It is only gonna process what is pumped or feed in to it regardless of the velocity of the water going by. Actually the odds would be in favor of it processing dirtier water at a higher flow rate. If you can view the sump and the display tank as one system which they are that might help with the understanding.

Makes sense, but, I have one more question to make sure I understand...

If we were speaking of a skimmer that has water plumbed directly to it (like an external skimmer) instead of through a sump, I can understand the higher flow rate. This is why air, water, oil, and gas filters slow down the flow of the substance that it is filtering, and all things flow faster (and dirtier) without a filter. But, let's keep in mind that just because you make the substance go through the filter quicker doesn't necessarily mean it is more efficient. It is well known that cheaper, or "high-performance" filters often let more dirty particles through to increase their "performance". This just means the filters let the substance go through faster, and doesn't necessarily mean that it is filtering at the same standard. True, a skimmer isn't a filter, but, water goes in and out of it after being processed, or skimmed...

But in a sump... It seems like the skimmer with a pump rated at 750gph, it'd be less efficient at skimming with 2,000gph of water rushing past it than the same skimmer with the same pump trying to skim 1,000gph since the pump more evenly matches the gph of water available to it. A skimmer processes water made available to it. Just because more water goes past it faster doesn't necessarily mean the skimmer is being more efficient, does it? That just means more water goes past the skimmer instead of through it. Regardless of how much water goes through the sump, the skimmer is only going to process so much. (I understand that part of your point.)

The flow in the tank was mentioned because the OP was factoring his closed loop into his equation. I can understand if we separate the closed loop, and only had the return pump, overflow and skimmer. In that case, it could stand to have a higher flow in the sump, if the pump of the skimmer was upgraded to a pump that processed more gph and drew more air as well.

True, the skimmer is only going to do all it can do, but, wouldn't it still stand to reason that the more time the water spent around the skimmer (in the sump), the more the water would be skimmed before re-entering the tank (looking at things as if they were all one system)?

 

[grouper therapy]

CedzAquAddiction;850308 wrote: Makes sense, but, I have one more question to make sure I understand...

If we were speaking of a skimmer that has water plumbed directly to it (like an external skimmer) instead of through a sump, I can understand the higher flow rate. This is why air, water, oil, and gas filters slow down the flow of the substance that it is filtering, and all things flow faster (and dirtier) without a filter. But, let's keep in mind that just because you make the substance go through the filter quicker doesn't necessarily mean it is more efficient. It is well known that cheaper, or "high-performance" filters often let more dirty particles through to increase their "performance". This just means the filters let the substance go through faster, and doesn't necessarily mean that it is filtering at the same standard. True, a skimmer isn't a filter, but, water goes in and out of it after being processed, or skimmed...

But in a sump... It seems like the skimmer with a pump rated at 750gph, it'd be less efficient at skimming with 2,000gph of water rushing past it than the same skimmer with the same pump trying to skim 1,000gph since the pump more evenly matches the gph of water available to it. A skimmer processes water made available to it. Just because more water goes past it faster doesn't necessarily mean the skimmer is being more efficient, does it? That just means more water goes past the skimmer instead of through it. Regardless of how much water goes through the sump, the skimmer is only going to process so much. (I understand that part of your point.)

The flow in the tank was mentioned because the OP was factoring his closed loop into his equation. I can understand if we separate the closed loop, and only had the return pump, overflow and skimmer. In that case, it could stand to have a higher flow in the sump, if the pump of the skimmer was upgraded to a pump that processed more gph and drew more air as well.

True, the skimmer is only going to do all it can do, but, wouldn't it still stand to reason that the more time the water spent around the skimmer (in the sump), the more the water would be skimmed before re-entering the tank (looking at things as if they were all one system)?</em>

Contradictory statement. That is why I use the HOB skimmer as an example but let's say we take the in sump skimmer out of the sump and put it directly in the display tank with tremendous flow . Do you think it would clean the water better? I actually prefer the outlet of my skimmer to dump in the next chamber rather than the skimmed water to return to the skimmer so quickly. Let's look at it like this: Your display tank has a hypothetical level of 100ppm tds and your skimmer will only remove 40% of those solids from the constant water flow through it thereby reducing the filtered water to 60 ppm tds. Would you rather it remove 40% of the 100ppm water or 40% of the 60 ppm water that it just cleaned?

 

[grouper therapy]

Sorry for the hijack!!!!

 

[cedzaquaddiction]

grouper therapy;850362 wrote: Contradictory statement. That is why I use the HOB skimmer as an example but let's say we take the in sump skimmer out of the sump and put it directly in the display tank with tremendous flow . Do you think it would clean the water better? I actually prefer the outlet of my skimmer to dump in the next chamber rather than the skimmed water to return to the skimmer so quickly. Let's look at it like this: Your display tank has a hypothetical level of 100ppm tds and your skimmer will only remove 40% of those solids from the constant water flow through it thereby reducing the filtered water to 60 ppm tds. Would you rather it remove 40% of the 100ppm water or 40% of the 60 ppm water that it just cleaned?

Completely understand and agree...

Just trying to say that with your example, if the skimmer were placed in the DT, more water would be skimmed if the skimmer spent 1 hour in the water than it would if the skimmer spent 10 minutes in the water...

Edit:

grouper therapy;850368 wrote: Sorry for the hijack!!!!

LOL. Me too....

Hopefully his answer lies in here somewhere...

 

[grouper therapy]

CedzAquAddiction;850370 wrote: Completely understand and agree...

Just trying to say that with your example, if the skimmer were placed in the DT, more water would be skimmed if the skimmer spent 1 hour in the water than it would if the skimmer spent 10 minutes in the water...

Edit:

LOL. Me too....

Hopefully his answer lies in here somewhere...

That holds true no matter where the skimmer is placed in the system.

Edit: I'd stick with the smaller pump anyway.

 

[tinmanunited]

I have enough flow through the sump, got it!

 

[grouper therapy]

TinManUnited;850389 wrote: I have enough flow through the sump, got it!

Are you sure??????????/

 

[cedzaquaddiction]

grouper therapy;850390 wrote: Are you sure??????????/

Gotta love ARC. LOL...

This was fun, Man. Learned a couple of things. Hopefully TinMan got his answer...

 

[jmaneyapanda]

grouper therapy;850382 wrote: That holds true no matter where the skimmer is placed in the system.

Edit: I'd stick with the smaller pump anyway.

Dave, This is all under the assumption that the water volume is homogeneous for "pollutants". However, this may, or may not be true. For example, is the water at the surface of the aquarium (where the air/water interface is) "dirtier" than water at the substrate? Food for thought.

 

[grouper therapy]

CedzAquAddiction;850370 wrote: Completely understand and agree...

Just trying to say that with your example, if the skimmer were placed in the DT, more water would be skimmed if the skimmer spent 1 hour in the water than it would if the skimmer spent 10 minutes in the water...

Edit:

LOL. Me too....

Hopefully his answer lies in here somewhere...

grouper therapy;850382 wrote: That holds true no matter where the skimmer is placed in the system.

Edit: I'd stick with the smaller pump anyway.

jmaneyapanda;850461 wrote: Dave, This is all under the assumption that the water volume is homogeneous for "pollutants". However, this may, or may not be true. For example, is the water at the surface of the aquarium (where the air/water interface is) "dirtier" than water at the substrate? Food for thought.

Doesn't matter in relation to the statement I was responding to. More water would be skimmed in 1 hour than 10 minutes at the same location no matter where that ONE location is in the system.