Skimmer Challenged

[RegalAngel]

I want to install a Skimmer in a DIY rubbermaid (HDPE) sump and am not sure which Skimmer to purchase...lots to choose from, and likely most any will be fine for my needs.

At this time, I am running a FO tank as I am new again to SW aquaria after many years of away....but will eventually go to a reef setup.

300g SW Penisula tank 8'L x 2'W x 2.5'H) with an overflow on one end rated about 0-1500gph flow rate (two adjustable gates) that is available to the sump.

Return line will be a one inch to two 3/4" top inlets with a series of nozzles(above the water line).

I also have a closed loop filtration (mechanical cansiter - 125 sqft area, and 40 liters of Pond Matrix for biological filtration) that is separately run from the skimmer loop.

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Skimmer - SRO XP 5000 Internal cone skimmer any good for this? Or what else should I consider for a skimmer?

Return external pump - Thinking of a Pan World 150PS

Plan is to have about 500-700 gph from the overflow to the sump w/skimmer and then return most w/bypass back to skimmer area of sump.
Never had a skimmer before, so I am challenged about all the skimmer choices and how best to get it all working properly, but for now which skimmer is a good choice?
The sump/skimmer will be located in a closet and I will therefore need to keep some cover over the sump area to avoid high moisture in the closet...another potential issue.

Thanks for the thoughts,
RA

[sjm817]

How big is the sump?
XP 5000 or SRO 5000 (cheaper) would both be good.

The 150PS is a high head pump which you dont need for ths app. The 100PXX would be better. Why the bypass back to skimmer section? No real use for doing this.

[RegalAngel]

I will be using a small 38g rubbermaid with a 20g inside that for water leveling. Don't need a large sump as my biofiltration is located in the closed loop system with the 40 liters of Pond matrix (under tank).

So, just enough for the overflow to the sump and the skimmer to sit in and then dumps below to the 38g with a outlet to the external pump.

Not sure about the pump, and yes it is pressure rated for the two 3/4" lines and 16 nozzles. Recirc to avoid restricting pump and possibly run some biopellets with the bypass back to the skimmer area.

[sjm817]

There is no reason to avoid restricting the pump. Put a valve on it to throttle it back if the flow is too much. That is a very small sump for that size system. I would keep the return flow lower. I would use a smaller return pump. How will you deal with drainback from a 300G display to a 38G sump when power is off?

[RegalAngel]

Originally Posted by sjm817

There is no reason to avoid restricting the pump. Put a valve on it to throttle it back if the flow is too much. That is a very small sump for that size system. I would keep the return flow lower. I would use a smaller return pump. How will you deal with drainback from a 300G display to a 38G sump when power is off?

There are only two points where the water can drain to the sump...the overflow that will have the Durso risers that limit the outlet flow; the overflow weir also will limit the outflow from the tank to the overflow chamber to only 15g. The second point is the inlet but they are all above the water line in the tank or equal to the water line and therefore cannot sustain a siphon once the water drops in the tank.

The sump is small for the tank, but I am not using the sump for biological filtering, or a refugium, etc. like many...I have bio. filtering via the closed loop system. I really don't have much more room for a sump alot larger.


Q. Is there too high a sump thruput since mine is capable of 0-1500 gph, what should I run it at. If I go with the Pan World 150PS then I can get a higher flow, but not sure I need it.

Q. How much water can the SRO XP5000I process per hour compared to the sump thruput? Appears it will only catch a small portion of the thruput, but I am not certain of what it pumps. Is there another skimmer I should consider as an alternative? It seems as though the XP5000I has met with good reviews from users.

EDIT: BOUGHT THE SRO XP5000I AND THE PAN WORLD 150PS(I can restrict output as mentioned if necessary).

Q. How should I flow water to a reactor for some of these bio pellets if I want to try them; would not a bypass flow from the pump be good for that?

Thanks for the thoughts,
RA

[sjm817]

You will drain back whatever the height difference is from the running level of the weir to the lowest part of the weir. How do you know it is 15G?

Since the 150PS is a high head pump, it will be harder to throttle it back since a high head pumps is just that. A pump that still flows well with a lot of head.

Not sure what the throughput of the 5000 is but it will work fine. I wouldn't sweat it.

Yes, a bypass flow for reactors will work good.

[RegalAngel]

I have a 1.5" drop from the tank level I want to the bottom of the slots in the overflow weir.... 1" = 10g approximately, so that's about 15g.

I am planning on a larger Skimmer holding tank of 28g with a 6"-10" height of water for the skimmer that would equate to about 10-16 gal water in the Skimmer tank. At 800gph (not sure what I will have) thats about a turn over every 45-72 seconds..it will be covered with a hole for the Skimmer to stick through.

A bulkhead at 6" + will dump water to the 38g return tank below the Skimmer tank.

Q. I am having a real problem trying to understand how I will maintain the tank level at the correct height. If I fill the tank to the correct height, it will just drain to the sump (15g). Then if I add another 10g to the return tank, it will pump about 15g of the return back to the tank to equalize levels?

I add RODI water to the tank with an ATO inside the tank at the level I want. I don't understand how the level of water in the sump return can affect the tank level...ie what pumps out of the sump gets returned regardless of the amount of water in the sump. Yet some use an ATO in the sump? Brain can't get a hold of this for some reason.

Seems like I will need to adjust the gate valves on the overflows (two 1.5" drains w/Durso pipes) to get the height on the overflow weir (tank level) to be where I want it. Otherwise, the water will just drain out as fast as it goes to the tank via return pump, and I will never get the height needed.


1. If I open the drain valve full(est. 1500gph max overflow) then what gets pumped out by the return pump will give me a height in the tank equal to the level on the overflow weir equal to the gph at that height. BUT that may not be the height I want in the tank.
So, to get the level I want probably higher than overflow full open, I will need to adjust the gate valves on the overflows more closed to raise the level. This will then slow the flow to the sump to meet the amount being pumped back to the tank in time...will drop level in sump initially as the tank level rises to my required height.

Seems then to be a delicate balance with the overflow gate valves to maintain the height in the tank....as evaporation occurs the water via the overflow will decrease and level in sump will drop as the return pump maintains same gph. As the level increases in the tank with ATO added at tank the overflow can increase bringing the level in the sump back up.

Do I have this corect?

[sjm817]

1.5" running level to non running level seems high. Usually it is less than that. It depends on the weir design and the amount of flow. Yes, what drains back is that difference plus what is in the return and drain plumbing. Fill the display and let it overflow to the sump. Fill it to the point of maybe 2" from the top of the sump. Turn on the return, let it run and see how low the sump level drops. Turn the return off and it should be just a bit higher that it was, but should hold it. Turn it back on and remove some sump water if it is higher than you want it to run at.

DO NOT put valves on the overflows to raise the level unless you like SW all over your floors. You run the overflows open. The level will be where it will be and will be constant. The evaporation level change will be seen in the sump.

[RegalAngel]

As I said I have the ATO level in the tank and water is added to the tank.

Some have the ATO level float in the sump, but they must add the water to the tank not the sump, correct. Changing the level of water in the sump won't affect the level in the tank as the return pump flows the same to the tank regardless of the sump level.

ugh, skimmer/sump challenged.

[sjm817]

You can have the ATO go into the display, but the float sensor must go in the sump. The display level does not change. It stays constant because of the overflow weir.

[RegalAngel]

Originally Posted by sjm817

1.5" running level to non running level seems high. Usually it is less than that. It depends on the weir design and the amount of flow. Yes, what drains back is that difference plus what is in the return and drain plumbing. Fill the display and let it overflow to the sump. Fill it to the point of maybe 2" from the top of the sump. Turn on the return, let it run and see how low the sump level drops. Turn the return off and it should be just a bit higher that it was, but should hold it. Turn it back on and remove some sump water if it is higher than you want it to run at.

DO NOT put valves on the overflows to raise the level unless you like SW all over your floors. You run the overflows open. The level will be where it will be and will be constant. The evaporation level change will be seen in the sump.

Ok, yes the height will be in relation to the overflow and return pump amount....with the overflow always being excess of what is needed. So, this will provide a "Height" in the tank above the bottom of the slots in the overflow, but I need/want a certain height. If I add water it will just drain to the sump and not give me more height. So, if I close the gate valves some it will raise the height, but like you said if you close too much then the pump out does the overflow and drains the sump and raises the tank level maybe too much.

I have another 10 gallons above "my height" so, there is some slack, but not much.

My ATO float is for this height only and my need adjustment then to compensate....I guess that is why they use the sump for this level? Much easier with just the closed loop!

EDIT: Ok, yeah I see you say to put the float in the sump...right, I get that.

[sjm817]

If you want to raise the running height in the display, block off the bottom of the weir slots.

[RegalAngel]

Originally Posted by sjm817

If you want to raise the running height in the display, block off the bottom of the weir slots.

Yes, I can do that, and that will raise the level in the tank.

If, ever change the flow from the pump, ie bypass more or restrict flow then this tank level is going to change as there will be less water going to the tank and therefore less going into the overflow and therefore the height on the weir will drop.

Seems like a slight adjustment to the overflow outlet gates ( I had these to adjust when it was a closed loop) would allow for easier adjustment to the tank level compared to weir blockage considering pump flow adjustments may be needed. But I understand the risk. If the pump has a consistent flow it will work ok, so I will probably try this route for awhile to raise the tank level.

With the full open gates then the flow to the sump will surge as the water rises and falls in the Durso inlet. The level in the sump return will be maintained as the flow coming in equals the outflow. In this case average overflow will match return flow, but overflow will not be linear flow but sine wave like.

With the overflow restricted with the gates being closed some then the Durso flow will be more consistent and not surge as much. Overflow then will be more linear compared to nonrestricted flow and will match return flow on a shorter time frame compared to unrestricted flow.


Once last thing on the ATO water additions. I see now that it does not matter where the water is added. As I was currently doing adding the water would raise the tank level. That will no longer be the case based upon the above. So adding water to the sump or tank will suffice. But measuring the level in the sump will be important, so I will move the ATO and RODI pump to the sump area.


I appreciate your thoughts as this is new to me and understanding what is going on and how to make sure this is setup best certainly takes some time and understanding to avoid problems.


Overlyconfused in Reefdom

[sjm817]

Restricting the drains will not change display height. The height of the display is controlled by the weir and flow through it. The level inside the overflows is lower. Closing off the drains will increase height inside the overflow, not outside (display). Why are you worried about display height anyway? Is this a rimless tank?

Why would the Dursos surge and be sine wave like? If they are set up correctly, everything is stable.

Yes, the ATO float must be in the sump. It makes no difference where the topoff is added.

[RegalAngel]

Yeah, I guess that is correct.

Hum, well I do have a canopy that currently just covers the water level, so that is what I am shooting for as a level. Lower level and inside of the top is visible. Higher and not a problem.

If I close the drains completely the height will rise as there is no where for the water to go, and the sump would drain and overflow the tank. If I closed them some then would there not be a location where it would rise and stop?
Level in overflow matches tank level at that point?

Oh, well I will just see how far it comes up on the weir and maybe block off the lower portion with acrylic plates.

Overly confused in reefdom.

[RegalAngel]

Ok, how about this.....

Modified Durso with the inlet at the water level height that I want?

-The water level in the overflow can rise no more than the water level in the tank.
-With the Durso inlet at the water level I want(higher than normal with it usually below the bottom of the weir) then water would rise to "my level" and then drain (no restriction on overflow).
-If the pump flow drops the overflow height remains at "my level" and the tank would also...correct? It would overflow at a slower rate into the inlet than if I had a higher flowrate.

Maybe just a standpipe like arrangement.....I have nothing currently. Just a screw in strainers in each of the two 1.5" outlets.

[sjm817]

For surface skimming to work, the level inside the overflow MUST be lower than display level. If the level of the overflow is the same as the display, no surface skimming and you will have a slick in the display.

Overflow drains are not for adjusting display level.

It seems you are overthinking this. Typically the weir is set up so that the bottom of the teeth are just at the bottom of the trim. This way, when the return is running, the level is above the bottom of the trim by some amount.

[RegalAngel]

True that the overflow would not be used in the traditional way with water moving over the weir. BUT, the water going into the overflow pipes would be from the surface water and that is the same essential surface gunk that is to be delivered to the Skimmer.

The Durso could not be used in this application as it would be too tall. I could use a open top 1.5" pipe to the level I wish and with two and the flows involved it should work.

Maybe I'll try it

[RegalAngel]

Second thoughts with two open top drains...noise! Yikes.

I guess I will go with the cover up job on the weir. Try it first as is and then put some acrylic over the bottom to raise the level. Likely the best idea, and thanks for the tips. I am smarter about this whole skimmer/sump area than when I started.

Thanks for the help!

RA

[sjm817]

If the water doesn't fall into the overflow, it wont surface skim. You will have an oil slick on the surface. Trust me on this. Use Durso's that will have the water level an inch or so lower that the bottom or the wier. I would just leave the weir as is and try it. If the level is too low and you can see it, you can make something to block a little of the weir to raise it.

[cobra9]

Also keep in mind that the water in the tank will drain through the weir some after you turn power off. My 150 drains about 8 gallons of water from the tank when you kill power because the water lvl in the tank is not at the bottom of the weir when the return pump is running.

[RegalAngel]

Originally Posted by cobra9

Also keep in mind that the water in the tank will drain through the weir some after you turn power off. My 150 drains about 8 gallons of water from the tank when you kill power because the water lvl in the tank is not at the bottom of the weir when the return pump is running.

Yes, it is 15g at "my height", but it may not be with a sump in operation(probably less). Time will tell what height I achieve with the PanWorld 150PS and about 20' of 1" into two 3/4" vertical run w/ head of 5' and then 8' of 3/4" along each top side with sixteen 1/2", 3/8", and 1/4" nozzles. Hard to determine the backpressure from all this so I went with the pressure pump. I have two Reeflo Marlins on my closed loop but plan to only use one at a time now with the sump in use. The second Marlin will be in place as a backup.

Here is my former setup...the "tubes" (formerly with carbon) will now be Pond Matrix filled and placed under the tank. The UVs are also under the tank so that clears out the closet some to place the two Rubbermaid containers in place. Will place the 28g Skimmer tank above the 38g Return tank using a PVC bench over the 38g.....

http://bwclark.smugmug.com/Aquariums

[sjm817]

I see the issue. Not sure of the sump and return will be enough to raise the level that much. Again, its is a very simple fix. Just close off some of the bottom of the weir enough to raise the water level to the bottom of the canopy.



Another possible option is to lower your canopy. I would do that if possible.

[sjm817]

You seem to have a very good handle on this now. The wingnut adjustable weir should work well. Keep us updated on how it works out.

[RegalAngel]

Originally Posted by sjm817

I see the issue. Not sure of the sump and return will be enough to raise the level that much. Again, its is a very simple fix. Just close off some of the bottom of the weir enough to raise the water level to the bottom of the canopy.

I plan to make a small piece of acrylic that will have a plastic bolt near the top of it and secure to the inside of the overflow with a plastic wingnut. Adjustable so I can slide it up/down a slot in the weir to change water height in tank. This will only cover the center portion of the overflow, but that should work.