Do you need to max your return flow?

[WetShepherd]

I was thinking about the noise volume of my 55g tank - noise doesn't bother me but I wonder if it's unusually loud. With eggcrate tops, the water flow volume is about the same as normal speaking volume. If I called you on your cell, in your car, with the window down, you'd hear it over the phone. Maybe I should tweak it?

I'm not sure what my maximum return rate is, but I have a 750gph pump on my return line which is 15x the turnover compared to the usual 3-5, assuming it's living up to the claims on the box. I do have a valve on the return line so I can reduce the flow (post pump, not pre). I'm wondering if there is a downside. My tank is doing great so, as a rule of thumb, I check in here before making changes. In other words I don't experiment on my tank - that's what I had kids for

Note that there isn't a 'flow' issue in the DT as my MP10 and koralias can get me into the 40x range without considering the return flow. This is strickly about getting water down to the sump, the skimmer, heater and possibly a fuge later.

 

[Ron Reefman]

I guess it's loud... I think I can hear it out my window... no, wait... sorry, that's the Gulf of Mexico. Having that much flow in your sump isn't necessarily a problem. Noise is one issue with that kind of flow. And you sure don't want that kind of flow in a refugium or especially in a DSB. So is the noise at the water intakes in the DT or at the output in the sump?

 

[Korrine]

It's rated for 750gph, but you loose some with head loss(how high it has to pump). Anyways, part of the problem of rushing water through a sump is little contact time with a skimmer. Definitely don't do that through your fuge. Again, contact time is a huge problem here.

What are your goals with the sump? For example mine are to:
1) hide equipment such as my heater, temp probe, skimmer, top off stuff
2) more water volume
3)have a low flow fuge

Here are pics of my current tank which is cycling. It has water in the sump now that I've sorted through plumbing leaks.

tank

sump

 

[Palting]

Sounds noisy by your description, but it also seems you don't mind the noise.

In direct answer to your title, no, you do not "need" to max your return flow. If you don't mind the noise, your tank is doing great, then don't change anything, IMO.

But now you've piqued my curiosity . How is your sump set-up? Do you have a refugium? How big a skimmer? What brand and model return pump?

 

[aleonn]

I'd lower the flow a little bit. I found that too much flow through my sump leads to increased noise and microbubbles in my DT (despite having baffles in the sump).

Also, what kind of overflow do you have? I had a Durso standpipe that was quiet at the overflow and noisy in the sump. I switched to an Herbie standpipe which has been quiet throughout the system.

 

[WetShepherd]

Thank you for the replies - I know it's a bit of an odd-ball question.

In answer to the location of the primary noise source:
It's absolutely the top of the overflow (intake in DT). There may also be some sound from the air hose I have in the return pipe. I suspect the sound in the sump may be proportionately loud, but it's muffled by the doors on the cabinet.

In answer to how it's set up:
It's hard to get a decent pic of the sump under a 55 long so I've included a pic before I installed it (it's facing the wrong way in the pic).
Water from the overflow channels into the tube (filled with bubbly o2 goodness) between the filter socks, flows up and into the socks when they are present (I've started pulling them out for short periods of time). The next chamber houses my skimmer (Tunze DOC 9002 - small) and heater (Eheim Jager 150w). Presumably this is where my fuge would go if I can move those components out. The last chamber is where my return pump sits. The water could pass through the sponge for filtration, but currently there's enough flow that it spills over the final divider.

I am experiencing a great deal of trouble with my skimmer. After the first week it was working great - pulling some, but not lots of dark brown sludge. Now it's doing almost nothing. It either pulls the faintest green tinted water or, if I increase the bubbles by even the smallest increment, it just bubbles up and fills with water. Now that you mention the flow being an issue, perhaps these things are related?

In answer to goals for the sump:
Initially to hide my equipment and increase my water volume. Now that I've spent countless hours on RC and know a bit more, I'd love to get some macro algae in there.

 

[Palting]

Noise in the oveflow. Is this the built in oveflow with a Durso drain? Two things I did to decrease the noise. I raised the drain pipe, so that there is now a very small drop from the teeth to the overfloww water level, cutting down the "waterfall" sound as the water cascaded into the oveflow box. Then, I covered the top of the overflow box with a black rigid plastic cut to shape. This not only enclosed the overflow box, but also shaded it preventing algae growth in the box and tubing.

Skimmer issues. Not so sure too much flow is the issue with the skimmer. I have close to 1400gph running through my skimmer section, and I have no problems with setting the skimmate dryness or output. I would check the skimmer first. Are the airvents clear? Is the pump and impeller pinwheel clear? Is the skimmer sitting in optimum water level? Maybe the skimmer is just too small for the application?

That looks like a Proflex sump. Water is supposed to go through the sponges and then does spill over the final divider. Are you saying it spills over the second the the last divider?

 

[WetShepherd]

Noise in the oveflow. Is this the built in oveflow with a Durso drain? Two things I did to decrease the noise. I raised the drain pipe, so that there is now a very small drop from the teeth to the overfloww water level, cutting down the "waterfall" sound as the water cascaded into the oveflow box. Then, I covered the top of the overflow box with a black rigid plastic cut to shape. This not only enclosed the overflow box, but also shaded it preventing algae growth in the box and tubing.

You are correct on the design - and what a great idea - it's such a pain to clean. As for the return pipe - it's already at maximum high if I want my eggcrarte to lay flat. It sounds like you had better success with that though so I'll look at it again.

Skimmer issues. Not so sure too much flow is the issue with the skimmer. I have close to 1400gph running through my skimmer section, and I have no problems with setting the skimmate dryness or output. I would check the skimmer first. Are the airvents clear? Is the pump and impeller pinwheel clear? Is the skimmer sitting in optimum water level? Maybe the skimmer is just too small for the application?

Skimmer parts seems to be working the way they should - no salt encrusting anything (I have it set to shutdown 30 min a day, the restart seems to blow the salt away). If it were an issue of it being too small, wouldn't the primary symptom be that I have to empty it too often? (My understanding of the way the skimmer works may be over-simplified). The format of the skimmer is well suited to my limited space, but it's also very different from the other skimmers I've seen posted here. This was a LFS recommendation so I should dedicate some time to reading about them - will do so tonight.Link.

That looks like a Proflex sump. Water is supposed to go through the sponges and then does spill over the final divider. Are you saying it spills over the second the the last divider?

That's right, it hits the wall with the cutouts for the sponge seen at the bottom, and spills over the top because it can't pass throught he sponge fast enough. I think what gets through the sponge is the majority, but yes, it still overflows.

 

[Vinny Kreyling]

Remember - you have to clean the sponges for max flow.
With all the water returning thru socks you might even be able to remove them.

 

[Palting]

Wow, I can't believe your flow overwhelms those big holes with the sponges. What kind of pump do you have?

 

[WetShepherd]

Ooops forgot to answer that, sorry. This is it, but the 3000 model (under specs and sizes).

 

[Palting]

I have the 5500 model of your pump. Your 3000 model is rated at 775 gph, but has only a 550gph output with a 4 foot head. The smallest Proflex sump is rated up to 550gph, so it should be able to handle the pump.

I've always felt that the Marineland Maxi-Jets are under rated for flow, so that may be a reason for it overwhelming your sump. I would suggest putting a ball valve on the output to match the sump.

 

[milspec]

If the pump is not restricted, with the valve wide open is it still loud?
If I have to reduce return water to the tank, I install a T and put a valve on a pipe that will send excess water back to the beginning of the refugium. As you open the valve less water goes to the tank and more flow goes through the refugium. You don't need the flow through the refugium or sump to be very slow. This way you aren't putting back pressure on the pump.

 

[WetShepherd]

Yes, I have a ball valve shortly after the pump which would allow me to restrict flow (currently it's wide open). It I wanted to T-pipe any off I would have to replace it as Mil is suggesting.

I'm starting to consider adding a secondary sump/fuge in the next room so T-ing off might be a good way to go anyway. Thanks for all the help guys