External Pumps - Which would you recommend as effecient/cost effective?

[gcarroll]

Originally posted by RichConley
THe thing about that, is gcarrols suggestion is only valid if you believe that an injection skimmer running at 1000gph+ is really stripping everyything that goes into it. If its doing that, then sweet, run the return at that speed. If its not, you're just pushing dirty water back to your tank.

Sorry Rich but the reason my quote is valid is because optimal results from an injection skimmer are achieved when the water input into the skimmer is the dirtiest water. It makes no matter if the skimmer is 100% or 10% efficient because the outgoing water is always cleaner than the incoming water. If flow is kept low with an injection skimmer or in fact any non-recirculating skimmer, the water in the sump will always be much cleaner that the water in the tank. The reason for this is because you have restricted the source of the dirty water to the sump as well as the source of clean water to the tank. With a non-recirculating skimmer best results are achieved when raw water from the tank is the source water for the skimmer pump and all outgoing water is sent back into the tank without being re-skimmed. This is why many people have seen improved results from skimmers where the output of the skimmer was directed on the other side of their baffles. It is no different than those who suggest not feeding the refugium with pre skimmed water.

[DRC69]

Hey Greg,
So high turn-over is good right??? Is 7 to 10 times to much?? Or is more even better? What number should we try for?
Say on a 100 tank w/ 30 sump??
Thanks - I need help to understand.

[RichConley]

Originally posted by gcarroll
Sorry Rich but the reason my quote is valid is because optimal results from an injection skimmer are achieved when the water input into the skimmer is the dirtiest water. It makes no matter if the skimmer is 100% or 10% efficient because the outgoing water is always cleaner than the incoming water.

Greg, theres an incorrect assumption there: You're assuming that you are getting water of equal dirtyness when you run high flow vs low flow. THats incorrect. When you run a lower flow tank to sump, you get a much thinner 'slice' of the surface water. IE you get all the protiens, and a minimum of water. When you increase the flow, you're meerly adding more water to that mix, with a negligible amount of increased waste.

SO the faster you run your flow from tank to sump, the cleaner the water goign to the sump starts out.

[gcarroll]

Originally posted by DRC69
Hey Greg,
So high turn-over is good right??? Is 7 to 10 times to much?? Or is more even better? What number should we try for?
Say on a 100 tank w/ 30 sump??
Thanks - I need help to understand.

I can't give a recommendation without taking other things into consideration. It all depends on your style of skimmer. What skimmer do you have or plan on having? If you want PM me and I'll give you my # to call then you don't have to go back and forth with someone who can't type but 18 words/min.

Originally posted by RichConley
Greg, theres an incorrect assumption there: You're assuming that you are getting water of equal dirtyness when you run high flow vs low flow. THats incorrect.

No Rich I am not making an assumption. You seem to be implying that the water on the surface has 100% of the protiens and the remaining water in the tank has none. That is simply not the case!

Originally posted by RichConley
When you run a lower flow tank to sump, you get a much thinner 'slice' of the surface water. IE you get all the protiens

Ahhhhhhhhhh! Now I see where we lost you Rich. You are assuming that the surface water is where all the protiens are. Rich you know that they are called disolved organics for a reason right? All the protiens/organics are not at the water's surface.

Originally posted by RichConley
When you increase the flow, you're meerly adding more water to that mix, with a negligible amount of increased waste.
SO the faster you run your flow from tank to sump, the cleaner the water goign to the sump starts out.

And your statement would be true if the water beneath the surface was protien/dissolved organics free.

Rich If you read my statements from the beginning of this thread you would have noticed that I do not see a reason for having a return pump that exceeds the gph that the skimmer can process. If you have a needlewheel skimmer that takes in 200gph then I do not recommend running 2000gph for a return pump. but if you have a skimmer that can process 2000gph you are doing yourself a disservice by giving it 1/10th of the water it can process along with 9/10ths of the water that it has process already.

[RichConley]

"No Rich I am not making an assumption. You seem to be implying that the water on the surface has 100% of the protiens and the remaining water in the tank has none. That is simply not the case!"

Greg, skimmers collect gunk in the exact same process that causes your water surface to collect gunk. If it won't collect at the surface, your skimmer wont pull it out.

The point I'm trying to make is that you dont get significantly more protiens by running the water faster. You get more, yes, but the concentration is less, so the skimmer can't pull them out as easily.

I've run big high flow skimmers (ETSS 800), and even they benefited when the sump to tank flow was slowed down.

[gcarroll]

Originally posted by RichConley
it won't collect at the surface, your skimmer wont pull it out.

Come on Rich you and I both know that although surface skimming is efficient, organics also lie under the waters surface as well. If you can process the all the water on the surface as well as some of the water underneath as well, you are better off. But if your skimmer can't process both, you are better off skimming only the surface water.

[RichConley]

See, thats where I disagree, the surface is the greatest concentration of protien. When you dilute the source going to your skimmer, you make it less effective. Moving more water just dilutes the source.


Skimmers take advantage of molecules (not necessarily protiens) that have both a hydrophilic and hydrophobic end. If they have these things, they will end up at some air water interface, and not be able to escape it. Higher waterflow just increases the chances that these molecules stuck at the surface will get churned back into the water.

[gcarroll]

But if you direct that high concentration of protien in water that has been skimmed multiple times because you are restricting the flow of the cleaner water back to the tank????? Either way that water will be diluted.
Do you want it diluted into the cleaner water that has already been skimmed?
Or,
Do you want it diluted with water that is returning fresh from the tank? Right along with that surface skimmed water.

[tacocat]

It's a little bit of both actually. Many compounds (especially proteins) have varying degrees of polarity. Some have extremely hydrophobic portions, while others may not.

Saltwater in a reef tank is an ionic and anionic soup. The molecules and compunds found in saltwater are enough to keep some organic compounds dissolved.

[MJAnderson]

The original question of the poster was what is the most efficient/cost effective pump. Greg do you agree that the most efficient way to skim is surface skimming? If so, isn't the most efficient skimming setup is one that uses a pump that delivers surface skimmate only as fast as it forms? Yes you can get more by delivering more water, but your effectiveness decreases. There is a point of diminishing return.

[gcarroll]

Originally posted by MJAnderson
The original question of the poster was what is the most efficient/cost effective pump. Greg do you agree that the most efficient way to skim is surface skimming? If so, isn't the most efficient skimming setup is one that uses a pump that delivers surface skimmate only as fast as it forms? Yes you can get more by delivering more water, but your effectiveness decreases. There is a point of diminishing return.

MJAnderson, If you asked me that same question (based on my way of calculating), I would recommend a pump that would send 200-300 gph to the overflow. Is that simular to what you run or would recomend running for yourself?

[MJAnderson]

Right now I'm running about 170 from an Eheim 1250. Was hoping for a little more, but the 1260 was a bit of a leap in wattage and flow. Didn't want to pay for the additional electricity and deal with the additional heat to just dump 1/2 my output back into the sump.

[djperezo]

I really don't get this thread coz it seems to me that the original poster did not mention what type of tank is he running (sps, lps, softies, mix??) because I think this is very important in his decision.

I tend to agree with Paul and Greg in regards to high turn-over rates to the sump, not in regards to the type of skimmer being used (though this is also important), but as to having an sps tank.

Why? its because of the high turn over rate in the display tank itself. Every body knows this causes a lot of swishing and swirling of the water surface, and organics accumulated in the surface gets forced backed into the water column.

To get an idea, picture a tank with a polar and non-polar liquid together. As you will see they will seperated and depending on the density, one of them will be on the bottom. Now put into the mix the insane flow you hear nowadays like 90-120x (even more) turnover rate. You will see that the two won't be as distinguishable anymore, they looked mixed. (I can't count the times I did this in the lab with a 500ml beaker and a magnetic stirrer, but its cool to see the compounds flip positions after manipulating either one).

Greg did say that there is always organics in the water column, as to what percentage (vice versa with organics in the surface) depends on the flow in the main display. This is just an opinion, as to organics in reef aquaria behave diferrently (read Paul's [kimoyo] post, very informational) as they are attracted to O2. But i just don't see how there could be a whole lot more of accumulation (prolly just a small percentage) of organics in the surface in a high flow sps tank. Take it for what its worth.. Cheers

Dave

[gcarroll]

Originally posted by MJAnderson
Right now I'm running about 170 from an Eheim 1250. Was hoping for a little more

You see, we are not speaking different languages as one might have been lead to think. My calculation is suited for the equipment one is using. Not a one size fits all method as some have been led to believe.

Originally posted by djperezo
I really don't get this thread coz it seems to me that the original poster did not mention what type of tank is he running (sps, lps, softies, mix??) because I think this is very important in his decision.

IMO, my recomendation was based on the equipment for optimal results. True it would be a great setup for sps which you strive for a nutrient poor system. But if a nutrient poor system is not his goal, the better solution is to go with less skimmer. That change alone would also change my recommendation.

[RichConley]

Originally posted by djperezo
(high flow needed for sps)
Why? its because of the high turn over rate in the display tank itself. Every body knows this causes a lot of swishing and swirling of the water surface, and organics accumulated in the surface gets forced backed into the water column.

Dave

Dave, all my powerheads in my 58 (2xSeio820, 2x Maximod900s, 1xTunze6060...over 100x turnover) dont move my water surface all that much. Theyre all down low, where they can keep detritus in the water. I run <100gph tank to sump. I feed 5-6 times a day, and feed a LOT of food. I keep 10 fish, including a small tang, and a couple full grown centropyge in that tank, and I'm STILL walking that nutrient poor line where if I dont feed the tank for a day my SPS start to lighten up.

If 100gph can handle that, then it can handle anything.

[gcarroll]

Hey Rich you mentioned that lightening problem before and you told me you would post pics the next day but I never saw them. What happened?

[RichConley]

Originally posted by gcarroll
Hey Rich you mentioned that lightening problem before and you told me you would post pics the next day but I never saw them. What happened?

My tank is in tough shape right now, I moved a couple weeks ago, and lost a few things in the move, and then didnt realize that there was very poor airflow in the corner where I put the tank, and the first couple of days, it got to like 86+, but I still have some thigns that show the problem.

Grr, let me get some pics when I get home. Some of the stuff looks great, and its getting better (the purple tang helped...), but Its specifcally stylos, digi, etc, at about 18" down, getting really light. The stylo is groing quick, its just very light. The digi I'm pretty sure is dead. Acros at that depth look great.

The whole problem is, I can't get them any deeper, because theres no more tank....

(all the parameters are fine, mag 1350ish, Ca 450, alk 9dkh, non measurable nitrates/phosphates, 100x+ flow, etc)

[djperezo]

Originally posted by RichConley
Dave, all my powerheads in my 58 (2xSeio820, 2x Maximod900s, 1xTunze6060...over 100x turnover) dont move my water surface all that much. Theyre all down low, where they can keep detritus in the water. I run <100gph tank to sump. I feed 5-6 times a day, and feed a LOT of food. I keep 10 fish, including a small tang, and a couple full grown centropyge in that tank, and I'm STILL walking that nutrient poor line where if I dont feed the tank for a day my SPS start to lighten up.

If 100gph can handle that, then it can handle anything.

Wow, 100x+ turnover rate without water boiling, I guess like you said, it all depends on positioning over pumps, but that is great with 100gph in the tank/sump loop, you are achieveing a nutrient poor sys. I need to take a closer look at my sys, you might have something im missing.

[mkarston]

OK, fist off, this is a great thread with some really good information about water flow.

One thing I wanted to clarify is: We are talking about return pump size and flow rate, but really I think what is being discussed here is the flow being run through skimmers. My point here is, if I have a return pump that will push 1000gph of water, that doesn’t mean that I must have all of that 1000gph flow through the skimmer.

I am currently in the process of planning for and setting up a 210 gal reef. I plan to buy the following 2 pumps:

I was thinking I’d get a Sequence ReeFlo Dart for my closed loop $218 and ~ 2700gph:
http://www.marinedepot.com/md_viewI...dproduct=MM1136

And this Pan World 50PX-X for my return from the sump $139 and ~1000gph:
http://www.marinedepot.com/md_viewI...dproduct=JW1135

Between these two I would have a total 3700gph, 17.6x turnover in my tank.

I agree that there are benefits to having slower flow through the skimmer sections of the sump, but that doesn’t mean that this can’t be accomplished with a pump with larger flow.

What do you think about splitting the return from the overflow, so that only a portion of the water runs through the skimmer and the rest just get fed back to the return chamber to re-circulate back into the tank?

I haven’t yet heard any opinions on this or know anyone who is doing this, but to me it just seems like a logical way to maintain high water flow in the tank, while reducing the water flow through the skimmer, getting the most out of your skimmer?

Thoughts?

Craig

[MJAnderson]

Craig,

If you're not getting water to your skimmer, why do you want it going through your sump? Assuming you don't have a frag section in your sump, nothing else in there needs high flow. If you're running several things off your return I could see the need for more flow but for flow in the tank a CL or powerheads are more economical and efficient.

I don't know the head loss on those pumps, but the Pan World uses 90w for 1100 flow. By the time you get the water to the tank, flow has dropped to about 800? 1 Tunze 6060 costs the same and will generate more flow in your tank for 11W. It will cost you about $8 a month in additional electricity for the Pan World, give you less flow, and generate less heat.

[djperezo]

Originally posted by MJAnderson


I don't know the head loss on those pumps, but the Pan World uses 90w for 1100 flow. By the time you get the water to the tank, flow has dropped to about 800? 1 Tunze 6060 costs the same and will generate more flow in your tank for 11W. It will cost you about $8 a month in additional electricity for the Pan World, give you less flow, and generate less heat.

put a penductor/eductor at the end of the Pan World and it will be pushing 5g more for every gal that pump pushes. So when using your assumed 800gph due to head loss, that will 4800gph total! I think thats better than having 5 huge 6060s in the tank.