Constant conundrum - Overflow valve GPH VS return pump GPH, how to keep water levels stable?

[Albertoinbox]

I probably "didn't get the memo" since this issue is too basic.

How can you have a variable return pump GPH and a fixed overflow valve GPH without having flooding issues in the overflow box and the sump?

This is rendering my protein skimmer useless since it floods everyday and cant keep the salinity stable. To me, the solution would be to open the overflow valve all the way and let the return pump oscillate the GPH freely, but I'm sure thats not the proper way to do it. Besides, If I do that, the level in the overflow box lowers to its minimum and the noise generated from the water going down the pipe in the overflow box is incredibly loud, not an option.

Also, from what I saw in a video, the water level in the overflow box is supposed to be approximately 1cm below the tip of the overflow pipe, but thats impossible due to the increase/decrease in GPH being pumped by the return pump into the tank while the overflow valve maintains a steady GPH flow to the sump.

Please check the following diagram:

 

[TangerineSpeedo]

As long as your the max GPH on your overflow is greater than your return GPH you should be fine. Set the return pump to the flow you want, adjust the valve on the overflow so that your water just trickles over the emergency. Then add or subtract water in your sump to the proper height.
Note: Turning on your skimmer you will have to add more water to your sump to equal the volume of water in the skimmer.
Note: Yes some ppl. run the overflow water level to just under the emergency height but that never worked for me.
Note: If you are running a Red Sea tank with the stock piping nothing you do will work. It will be in the "ballpark" but the overflow never stays at a constant height.
Note: On your Overflow valve you need a "gate" style valve to be consistent.

 

[Albertoinbox]

As long as your the max GPH on your overflow is greater than your return GPH you should be fine. Set the return pump to the flow you want, adjust the valve on the overflow so that your water just trickles over the emergency. Then add or subtract water in your sump to the proper height.
Note: Turning on your skimmer you will have to add more water to your sump to equal the volume of water in the skimmer.
Note: Yes some ppl. run the overflow water level to just under the emergency height but that never worked for me.
Note: If you are running a Red Sea tank with the stock piping nothing you do will work. It will be in the "ballpark" but the overflow never stays at a constant height.
Note: On your Overflow valve you need a "gate" style valve to be consistent.

I have a RED SEA Reefer 350

Yes, if I keep the RP GPH stable I can achieve that, but then, why is the return pump GPH even programmable If I have to keep it stable? I don't think Neptune (and many others) went to the length of making its pump soooo smart just so it can function with a fixed GPH, theres got to be an explanation. I actually posted this question on their forum a couple of days ago and so far got many views but no reply...

I would like to run different GPH to provide a dynamic environment that would benefit life in the tank, rather than a dull, constant current, seems obvious enough and I guess thats what the manufacturers had in mind. I see people programming all kinds of GPH variations during the 24 hour period, how do they keep water levels stable?

In this link RED SEA says to keep the level in the overflow box 6-12mm below the overflow pipe by controlling the overflow valve, BUT AGAIN, that wont work if your return pump's GPH oscillates, correct?

REEFER™ 250 V3A - Support page | Red Sea

Find all manuals, spare parts, sump drawings, FAQ & how to videos

g1.redseafish.com

I guess their excuse would be that these instructions consider your return pump has to have a constant GPH. BUT they also make smart return pumps with variable GPH that you can program through the app, so I guess I'm going to have to shoot them this question on their website and we'll see what they say. Maybe they upgraded their tanks with a "gate" style valve like you mentioned.

I'm just mind boggled that there actually isn't (to me, so far) an explanation for this after all this time. How do people keep a starfish with these salinity variations???? You need a 500 gallon tank to buffer out all the inconsistencies?

Thank you.

 

[TangerineSpeedo]

The dynamic aspect of a pump is not for a return pump. The variable speed aspect of it has to do with using it on a close loop system, not an overflow system. (look at @Tidal Gardens systems, Than uses closed loop systems in conjunction with his overflow systems. For your RS reefer you will have to use an additional powerhead inside your display to get a variable flow ( Gyre, Nero, Mp40, Jebao etc.) Your return pump has to be constant. The reason why you have different speeds is, if your pump output is X and you add a manifold to your return pump then you have to increase X to maintain the same amount of flow.
I have a RS 170 and will always have fluctuations in the overflow. On that tank I run the level so it trickles over the emergency also. And yes I do have a Sea Star in that tank.

 

[Albertoinbox]

So, got a reply from red sea (that was quick):

"If the return pump is fluctuating in flow rate throughout the day, there is not a sure way to keep the water level in the overflow box at the same level without also adjusting the downflow valve each time, which in turn adjusts the rate at which the water empties into the sump."

The obvious conclusion is that the return pump then has to be set to a fixed GPH for life (with adjustments for change in equipment), like you said. That automatically takes me to the next question:

Why would RED SEA advertise that you can "Set a customized daily schedule with varying intensities" for their return pump if that is going to bring you problems? (I replied to them with this question)

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redseafish.com

Funny that they put "schedule" right after "peace of mind" when they are opposed to each other...

 

[KStatefan]

Use flow pumps in the tank to give variable flow in the tank. Keep your return pump constant.

 

[Albertoinbox]

Use flow pumps in the tank to give variable flow in the tank. Keep your return pump constant.

Yes, yes, that just contradicts what the manufacturers of the smart pumps advertise. I bet a lot of people are going with it and setting up all kinds of GPH throughout the day and having issues. Like me.

Current in the tank may be controlled by powerheads but increasing/decreasing return pump GPH will also increase/decrease the rate at which the water is filtered by the sump and the rate of exchange of the water volume in the display tank, which you could probably use as a benefit.

 

[blecki]

The pump is a pump, not a return pump.... Different applications have different requirements. Why would they not advertise all the features of their pump?

 

[Albertoinbox]

The pump is a pump, not a return pump.... Different applications have different requirements. Why would they not advertise all the features of their pump?

Thats generalizing and moving away from the issue, I'm being very specific here.

The pump adjusting feature is good, they should advertise it, just not in a way that cant be used to the benefit of the customer. Its like saying your car has the feature of being able go up an incline of 30 degrees then advertising you can use that to jump a ramp over the grand canyon.

 

[Albertoinbox]

So, got another reply from RED SEA (amazingly fast response):

"Our pump has a wide variety of aquatic applications and were not designed exclusively for REEFER systems. The varying intensities feature can be helpful in certain applications but if utilized in a Reefer aquarium, this feature unfortunately will result in fluctuating water levels in the sump and overflow box. The downflow valve is not able to automatically adjust itself as the pump's intensity varies. However, in theory if you start and end the day with the same intensity, then the water should start and end the day with the same level in the overflow box."

Thats a polite way (staying away from liability) to say you shouldn't use it if you own a reefer system. Why isnt this information on the product page anyway?

In fact, I have NEVER read anywhere that you should NOT use this feature to vary return pump intensities throughout the day if you have a reefer system (or ANY system). They just put the information like this out there and consumers get confused, especially if you're a new consumer in the hobby.

I say the information available on the product page is very simplistic and incomplete and perhaps misleading (it was in my case), especially when you have a reefer system in the background and the different pump intensities throughout the day in the app on the foreground.

ALL the manufacturers of smart pumps advertise this feature like this, not just RED SEA.

I wonder how many people (%) in the community know you're not supposed to use this feature and are going through a huge hassle like me. You must understand that this hobby can be VERY frustrating and correct information is gold. To be mislead or not be given correct information on such a basic issue is, well...frustrating!

 

[KStatefan]

Yes, yes, that just contradicts what the manufacturers of the smart pumps advertise. I bet a lot of people are going with it and setting up all kinds of GPH throughout the day and having issues. Like me.

Current in the tank may be controlled by powerheads but increasing/decreasing return pump GPH will also increase/decrease the rate at which the water is filtered by the sump and the rate of exchange of the water volume in the display tank, which you could probably use as a benefit.

I have not seen any pump manufacture recommend fluctuating the flow for a return pump if used in a closed loop yes.

If you seen the benefit continue to do so.

 

[Albertoinbox]

I have not seen any pump manufacture recommend fluctuating the flow for a return pump if used in a closed loop yes.

If you seen the benefit continue to do so.

No, not as specifically as you put it, they are much more generic.

Don't you think this can make you think you can do it? Reefer in the background, app in hand with different flows set at different times of the day and the text on the bottom "Set" a customized daily schedule with varying intensities? (Doesn't mention "not for use on a reefer system" anywhere).



Or this? Why would you set up a minimum and a maximum flow?



What benefit I've seen are you talking about? If I recall correctly I only mentioned the disadvantages.

Thanks for pitching in.

 

[BeanAnimal]

I wonder how many people (%) in the community know you're not supposed to use this feature and are going through a huge hassle like me. You must understand that this hobby can be VERY frustrating and correct information is gold. To be mislead or not be given correct information on such a basic issue is, well...frustrating!

Variable speed is just a feature - it is up to the equipment owner to determine how to use the feature. Nobody mislead you, rather you don't (didn't) have the knowledge required to understand the feature.

You now learned something new

 

[BeanAnimal]

Or this? Why would you set up a minimum and a maximum flow?

Example: Some people may program the lower speed for feeding time. Lower flow means less food going into the sump. Depending on the setup, the overflow may just be noisy during this reduced flow, or may be self adjust (mine does).

Likewise, not all of us have skimmers that are in a variable water level compartment. My skimmer runs with or without the return pump running and is not affected by sump water level.

As others have mentioned, the variable flow is extremely useful for closed loops. It is also useful for skimmers, where they can be ramped down but not off during feeding, etc.

 

[BeanAnimal]

Also - if you have (TWO) return pumps set to oscillate opposite of each other (sinusoidally 180 degrees out of phase for example) then the flow from sump to tank would be steady but would oscillate between the two pumps...

There are plenty of creative ways to use variable speed pumps, even as return pumps.

 

[danR777]

I also like how I can lower it down my cor-20 to 1% on a feed mode and then slowly ramp it back up , instead of bursting it back on full blast where you would do on an ON/OFF of a return pump