Varied flow, critical or not?

[BornHandy]

I am getting my build together, and just can't stomach the idea of power heads in the tank.
The stats:
75 gallon tank
Neptune Cor 20 pump

I was thinking of either running a single pump at 800 gph, splitting off with a T fitting so that each side of the tank gets two lockline nozzles blasting in, making just some turbulant, but high flow water.

...or, running 4 lockline nozzles on one side to get the gyre effect.

...or, either one with random flow generators on some or all of the locklines.

I am also going to run the bean-animal overflow, so ramping the pump up and down probably won't work, so what does the community think? Is varied flow really that important? I seem to remember lots of successful tanks back in the day that didn't have the varied flow, or did I dream that up?

 

[sghera64]

Your 800 gph pump will like be delivering 500-600gph once you account for head loss due to fittings and lift height.

Are you running bare bottom or sand?

 

[Mebbid]

How about a closed loop system hidden in the rocks?

800 gph is pretty low flow for a 75g.

 

[sghera64]

I put my two Jabeo RW-20’s behind the rock along the back wall.

I can generate random flow and move a lot of water with both on max random pattern and behind the rock. But, behind the rocks, it cannot generate much of a “standing“ wave.

 

[BornHandy]

Thanks for the replies.

Sghera64, the pump is capable of 2000 GPH, and tunable. The 800 gph is a target I plan to hit by tuning, so I have accounted for the loss, but thanks for the heads up. About the Jabeo RW-20’s, I saw some in action on someone else's tank, and they were really noisy. Are yours quiet?

Mebbid, you think so? I was planning on the Triton method, so I came up with that as a 10x total water volume estimate. What do you think is optimal?

 

[PDR]

Yeah, that is really low flow, even at 800gph. What kind of coral do you plan to keep? I keep basically all soft coral and I still have about 3000-3500gph in my 75. My jebao pp and ow's are both silent unless I'm up against the glass, but I use the smallest pumps, the large ones may be louder.

 

[Bpb]

It really depends on what you plan on keeping. Lots of adjectives get used to describe flow but it's important to know we are all on the same page with them. By varied flow, do you mean flow that changes often in intensity, or flow that changes direction and intensity?

Flow coming from a single source will be laminar. It'll only ever push things one way, and will cause dead spots. Are dead spots all that bad? Maybe, maybe not. Kind of depends on your goals. It can become troublesome with stony corals though, as they will tend to grow in the direction the flow is running, and you cannot reverse that. If you have soft corals they'll always be leaning one way.

I tend to prefer having flow that comes from opposing directions, that alternates intensity. The conflicting flow streams create random turbulence that helps discourage dead spots from forming, and gives your corals uniform current, allowing for more symmetrical growth. Ive used Vortechs, Tunzes, jebaos, and Koralia. The jebaos were kind of in the middle on noise. By no means loud. Tunzes were 100% silent even on 100% and youd have to visually observe the impeller spinning to verify they're actually working.

 

[madweazl]

Triton's recommendation of 10x flow through the sump seems rather arbitrary; I've messed with 3x-10x and never noticed a difference on the current setup.

When it comes to flow within the display, 10x is very low for all corals/anemones. By comparison, I have a pair of MP40WES running at 100% in my 75g

 

[BornHandy]

Bpb, any variation at all. I really don't want to include powerheads in the display if I can avoid it. That leaves me with the option to do dual return pumps, and simply alternate the flow rates from one to another for long periods - I feel like that would do the job.

That is almost a problem solved, but this aquarium is in the living room, so noise is a concern. For that reason, I have opted for a bean-animal overflow, and I need a constant turnover rate through the sump in order to maintain a perfect siphon. I don't think I can program a controller to maintain exactly a given gph from two pumps (one pump ramps up as the other ramps down).

In the end, I am going to do what is best for the inhabitants, but I want to avoid powerheads if at all feasible. This is why I considered those random flow generators for the lockline, but I am not convinced they can replace a couple of powerheads or better yet, two return pumps alternating the return flow.

I am even considering adding ball valves to the return pipes so that I can manually close off portions of it from one day to the next, and I think that would also do the job, but with longer periods of a given flow pattern.

 

[Mebbid]

The 10x total water volume in triton method is sump flow through. For a softy and lps tank probably 20x display volume would be sufficient while a sps and acro tank likely needs on the order of 30x or more.

Without using powerheads, realistically the only way to achieve these goals is a closed loop system which unfortunately is a logistical nightmare for maintenance.

Some options for powerheads that might work (which are unfortunately expensive) are maxspect gyre pumps or mp10 / 40)

The maxspect has to be mounted very high in the tank and creates an awesome flow pattern. The height of mounting them makes them stick out a little less.

The ecotech mp pumps run without a cord in the tank so are less invasive in that way.

The last option I can think of is to disguise the powerheads with a DIY or store bought stone that fits over the powerhead and makes it look like a rock.

 

[TheHarold]

If you are constantly pushing one way, growth looks uneven and odd.

 

[Vivid Creative Aquatics Verified Sponsor]

I am getting my build together, and just can't stomach the idea of power heads in the tank.
The stats:
75 gallon tank
Neptune Cor 20 pump

I was thinking of either running a single pump at 800 gph, splitting off with a T fitting so that each side of the tank gets two lockline nozzles blasting in, making just some turbulant, but high flow water.

...or, running 4 lockline nozzles on one side to get the gyre effect.

...or, either one with random flow generators on some or all of the locklines.

I am also going to run the bean-animal overflow, so ramping the pump up and down probably won't work, so what does the community think? Is varied flow really that important? I seem to remember lots of successful tanks back in the day that didn't have the varied flow, or did I dream that up?

In a 75 gallon display, a coupe of 3/4in RFG Nozzles would be a great choice. If you can provide each nozzle with at least 400 GPH (or more) you may be able to reduce the number of or even eliminate your power-heads.

Ideally, you would want the 2 nozzles setup with one on either side of the tank opposing each other, but if you have them coming in on the center of the tank, then you would want to pointed them more forward facing but jst tilted slightly towards the corners.

 

[Vivid Creative Aquatics Verified Sponsor]

Also - as a side note - you'll get better results with fewer RFGs at higher GPH per nozzle than more RFGs at lower GPH per nozzle.

Your goal should be to get the flow going to the nozzle to fall within the Optimal Suggested GPH rating for the size nozzles you select to go with. Size them according to what kind of GPH you can provide them.

You'll find the ratings for each nozzle size in our FAQs
https://vividcreativeaquatics.com/frequently-asked-questions/

hope that helps.

 

[Bpb]

Sounds like sea swirls are your winner

 

[sghera64]

Thanks for the replies.

Sghera64, the pump is capable of 2000 GPH, and tunable. The 800 gph is a target I plan to hit by tuning, so I have accounted for the loss, but thanks for the heads up. About the Jabeo RW-20’s, I saw some in action on someone else's tank, and they were really noisy. Are yours quiet?

Mebbid, you think so? I was planning on the Triton method, so I came up with that as a 10x total water volume estimate. What do you think is optimal?

Yes, my RW-20's in the DT are quiet. I can hear them IF I turn my AC return pump off. My RW-8's (in the frag bins) are even quieter. A noisy Jebao is a sign of either needing a shaft and prop cleaning or a worn-out bushing.

 

[hart24601]

I would try some of those RFG if you are really attempting to avoid powerheads, but it seems to me that in the past few years flow is finally getting recognized as being tremendously important to our systems. Many reefers now consider flow more important than lighting, within reason, and second only to keeping the chemistry inside established parameters particularly when dealing with SPS. While I can understand not wanting them, I would 1st try the RFG and think of the tank as more of a lagoon system and keep fleshy LPS like bubble coral – not that they don’t need good flow of course.

 

[Skep18]

What kind of coral do you plan on keeping? (I apologize if I missed it)

 

[Larry L]

I have some gyre pumps in my tank but I recently added a @Vivid Creative Aquatics random flow nozzle on my single return line, and was very pleasantly surprised at just how much more random the flow in the tank seems to be. They're really inexpensive - probably the biggest bang-for-the-buck thing I've done for my tank in a long time.

 

[BornHandy]

Mixed reef. Heavy on the LPS with a SPS now and then. I am just about resigned to add a power head to the back and conceal it with the rock work.

There goes even more money! The bottom line is, I want a show stopper of a tank, and if it takes power heads, then so be it. I am thinking maybe some of those RFG's can't hurt either.

Sounds like most are on the side of varied flow being critical. I think one thing we can all be sure of is that it doesn't hurt, so better safe than sorry.

 

[PDR]

Mixed reef. Heavy on the LPS with a SPS now and then. I am just about resigned to add a power head to the back and conceal it with the rock work.

There goes even more money! The bottom line is, I want a show stopper of a tank, and if it takes power heads, then so be it. I am thinking maybe some of those RFG's can't hurt either.

Sounds like most are on the side of varied flow being critical. I think one thing we can all be sure of is that it doesn't hurt, so better safe than sorry.

If that is your goal, you will definitely need multiple powerheads. If you have a chance, watch this video.