How Much Flow is too Much?

[SkullV]

Had a small argument on another forum and figured I would pose this question here as well. "For an SPS tank, how much flow is too much?"

I have 3 WP10 powerheads putting out approx. 1000gph each on my 20g long nano SPS reef and it seems to me like the coral loves the flow. No coral has direct flow from a powerhead being pointed right at it, which I agree is generally not ideal. Everything has great polyp extension, growth seems good, color is fantastic, and nothing ever settles on the sand.

I was told "three WP10s in that tank is overkill", "that much flow will slow sps growth", and "keep some more delicate sps species with that much flow and it will humble you (I'm not sure exactly what species he was referring to)".

My argument was not only does everything in the tank seem happy but even at 165x turnover with my return pump included, I'm nowhere near the amount of flow that these corals get on the real reefs.

So what do you think? Would love to hear some more opinions.

 

[bogg]

How about a video with close ups of the polyps

 

[SkullV]

How about a video with close ups of the polyps

I can take one tomorrow when the lights are back on. Do you have an opinion about flow level?

 

[phenom5]

IMO this is why the Riptide (and potentially future competitors like it) will be successful. Volume is only part of the equation. Velocity also plays a big roll.

 

[SkullV]

IMO this is why the Riptide (and potentially future competitors like it) will be successful. Volume is only part of the equation. Velocity also plays a big roll.

Are you referring to more direct, faster flow across the polyps? Would you say there is no such thing as too much flow then?

 

[phenom5]

Lower velocity.

Wide output means the pump can move a high volume at a lower velocity, which mimics the natural flow on reefs (better at least).

It's the same reason Tunze, Vortech, Jeabos, and all the other prop pumps have replaced the older impeller style pumps for in-tank flow. Prop pumps move high volume at a lower velocity than an impeller style pump. The Riptide is the next step...at least, in theory, given that I haven't seen one in action in person.

 

[Peter Eichler]

I would say what you have is overkill, but not too much.

 

[SkullV]

Lower velocity.

Wide output means the pump can move a high volume at a lower velocity, which mimics the natural flow on reefs (better at least).

It's the same reason Tunze, Vortech, Jeabos, and all the other prop pumps have replaced the older impeller style pumps for in-tank flow. Prop pumps move high volume at a lower velocity than an impeller style pump. The Riptide is the next step...at least, in theory, given that I haven't seen one in action in person.

Ah, interesting explanation, I definitely agree.

I would say what you have is overkill, but not too much.

Would you mind explaining why you believe it is overkill? I'm not against reducing the flow at all if it is something that will help the tank in the long run.

 

[Dapg8gt]

^^agree it is imo overkill for the small tank but if the corals are not affected or loosing tissue it's not too much.. I think What you will probably get is either corals growing thicker shorter branches or different growth patterns in general than typical colonies. That's just my guess though.. I also have more flow than the average bear in my tank.

 

[SkullV]

^^agree it is imo overkill for the small tank but if the corals are not affected or loosing tissue it's not too much.. I think What you will probably get is either corals growing thicker shorter branches or different growth patterns in general than typical colonies.

Interesting thought about the growth patterns. Maybe that's what the guy on the other forum meant by "slower" growth. I don't know that it would be slower but could certainly see the growth changing to accommodate the coral based on flow.

You didn't explain why you believe it is overkill though. Would you kind expanding?

 

[Hexacorallia]

^^ growing different patterns is exactly what should happen. From general morphology of corals I can get a great idea of flow requirements.

 

[SkullV]

^^ growing different patterns is exactly what should happen. From general morphology of corals I can get a great idea of flow requirements.

When you say is what should happen, do you mean that is a good thing or is just something that is inherent with high flow systems?

Would love to hear some more opinions on this question. I know there are tons of experienced SPS keepers on here!

 

[jda]

If your branches are thin and whispy looking as the SPS grow, then you have too much. You can also get short stubby ones that just want to encrust, as described above. Whatever the volume, the flow needs to be effective - not all flow is effective. Something like a wavebox moves very little water, but it is effective and SPS grow with very nice patterns and have good PE even down in the shadows that is hard to duplicated in captivity. Back in the early BB tank days, people wore their flow rate as a badge of honor and I am not too sure that all of it was good.

I do use a wavebox since I love the growth patterns that they give with ease - waveboxes are not the only way to do this, just the most reliable that I have used. I also use a few tunzes at half power so that the fish don't have to work too much, but are also not getting blown all over the place.

 

[Amphiprion]

^^ growing different patterns is exactly what should happen. From general morphology of corals I can get a great idea of flow requirements.

Agreed. I'd expect to see less linear extension rates and more increases in density.

When you say is what should happen, do you mean that is a good thing or is just something that is inherent with high flow systems?

Would love to hear some more opinions on this question. I know there are tons of experienced SPS keepers on here!

It is inherent of high water motion systems, both aquaria and on reefs.

At one time, I had a Pocillopora colony that was about 8"x8" and weighed close to 10lbs. The branches were very short, thick and only emerged from the very top. As they grew, they anastomosed into a solid mass of skeleton.

 

[SkullV]

If your branches are thin and whispy looking as the SPS grow, then you have too much. You can also get short stubby ones that just want to encrust, as described above.

Are thin whispy branches unhealthy or just different than the norm for certain colonies? I personally don't prefer the thin branches, so if high flow will cause that I don't want it, but I'm trying to understand this idea of too much vs. different.

 

[Peter Eichler]

Ah, interesting explanation, I definitely agree.



Would you mind explaining why you believe it is overkill? I'm not against reducing the flow at all if it is something that will help the tank in the long run.

I just think it's more than you would ever need to have healthy thriving corals, but it's probably not so much that it's detrimental.

 

[Piper27]

I have noticed thin long skinny or whispy branches in tanks with not enough flow not tanks with too much. I keep lots of flow to avoid this look...

I love lots of flow, makes the corals grow thicker and more natural in my opinion. I had 2 wp40 s, 2 mp40s, and a wp25 on a 50 gallon shallow rubbermaid, so I don't think it's too much. If your corals are fine and growing the way you like then keep it going.

I also had a big red pocci get so big and thick it was just a big ball and was impossible to frag. Same thing happened with my blue stylo.

Also the heavy flow is not slowing growth imo, it's just making the corals more dense and thick. Which I think looks more healthy and natural. To each their own.

 

[reif119]

As long as it doesn't blast coral polyps off there skeleton you should be fine. A stronger water flow allows more water to pass over the corals which allows them to absorb more nutrients which in turn should increase growth rate. Not much more growth than normal but hey, us reefers need all the inches we can get

 

[Tweaked]

3 MP40s and an MP10 in my BB 105g tank. I love the wave mode :crazy1:

 

[JohnnyD88]

i have 150 gallon extra high dominate with sps and 10 fish. for flow i have two wp60 and two mp40 my sps it loven it at first the fish didn't like it but now they love it