Should I continue using powerhead in nano?

ashleyberg · Sep 27, 2021

Hey! Long time lurker, first time account creator and poster. I've been running my Fluval Evo 13.5g for about 6 months, and had corals and fish for 4. Whenever the powerhead is on, my clown stays strictly along the overflow/sump wall of the tank, and my yellow watchman goby stays in his cave. Yes, I do know that this is typical behavior of both fish (clown's to stay in a certain spot in the tank, and gobies to stay in their caves). However, whenever I turn the powerhead off, both fish start exploring the tank, and some corals also seem to open up/fatten up a bit more when the powerhead is off as well.

I was wondering on people's thoughts about running the tank without a powerhead. I think my turnover rate is 33.33 gallons per hour (based on the math posted online on how to figure it out). Without the circulation pump, it would be 13.7, which doesn't seem like enough, however my tank is softies and beginner LPS only. I also haven't seen any quality powerheads with lower GPH (besides the Hydor Koralia Nano at 240 GPH, which doesn't seem like a big enough decrease in GPH to justify the purchase) , so if anyone has a suggestion on another type I could try, that would be great!

Edit: Also, the pic attached shows the surface agitation and flow without the powerhead on. I also have a skimmer that I can run if oxygenation becomes an issue without a powerhead. Just thoughts!

Here's all the info on equipment that affects flow:
Fluval Evo 13.5g
Sicce Syncra 0.5 return pump (185 GPH)
Fluval Sea CP1 circulation pump (265 GPH)

Corals:
Aussie Multicolor Hammer
Purple Tip Hammer
Rose Gold Hammer
Indo Toxic Green Splatter Hammer
Mini Teal Cristata Torch
Various Ricordea Mushrooms
2 types of Zoa's
Discosoma Mushroom
Mandarin Firework Clove Polyp
GSP
Neon Green and Blue Trumpet
Candy Cane
Kenya Tree

Spare time · Sep 27, 2021

The way that I judge lps to be happy with flow is if they look tree branches swaying with the breeze outside. Too much would be like a tree in a storm. You don't want them being whipped, but you want their polyps to move around gracefully.

blaxsun · Sep 27, 2021

You could try turning it off for a week and watch for any changes.

jfoahs04 · Sep 27, 2021

Do you turn the powerhead off when you feed? If you do, your fish could be responding to that (thinking its feeding time).

I have a hard time imagining you have too much flow. I have the same tank, running the stock pump and a Nero 3 powerhead that peaks at just over 1,000 gph (about 30%). Prior to this, I was running a Current USA eFlux wavemaker at 100% (660ish gph). So 265gph should be a non-issue for the fish. I have a tailspot blenny and a small clown. Neither struggle with the flow and cruise around the tank, but both are most active when I shut it off to feed because they know what's coming. Your coral shouldn't have issues either unless it's pointed right at some of your nearby hammers. I have all sorts of softies and easy LPS and I only ever moved a frogspawn that didn't love being right in the flow (it's fine now).

Before pulling the powerhead altogether, I'd experiment with changing where it's pointed. You could turn it towards the surface a bit more, or point it at a side or back wall to "diffuse" the flow. You could also try keeping it off for a block of time. If you did remove it, the Siccee should be enough to move water and keep surface agitation adequate (so long as one nozzle is pointed at the surface) to keep the coral you have. But if you want anything more advanced, you'll want to have a bit more flow.

edit to add - this is my EVO with the powerhead running at 1,000gph pointed straight at the rear wall:

clifg · Sep 27, 2021

The other option is, if you have the stock return pump, to upgrade that to a sicce 1.0. They just barely fit but if combine that with the VCA RFG it puts out some really nice flow without having a powerhead in the tank.

Reef Jockey · Sep 27, 2021

I have a Evo as well and i do not have a powerhead. I did however upgrade my return pump to a Sicce 1.0.(couple of months ago) and am getting movement through the corals and nice polyp extensions. I have considered adding a powerhead like the Hygger mini wave maker but it's to early to determine if needed. If i see growth in the corals then i likely dont need it.

LIreefguy · Sep 27, 2021

The one person about said it best. If your corals look like a tree on a breezy day you are fine. If they look like a tree in hurricane sandy. Then you have too much flow on that coral
Flow is very important to long term health of corals
I wouldn’t take out powerhead, but like someone suggest. Move it around me experiment with different flow patterns

Reef. · Sep 27, 2021

You don’t need to worry about the turnover rate, as long as the corals and fish as happy, turn over is mainly for sps.

Flow is good tho as it helps reduce the chances of getting cyano etc and helps kick up detritus into the water column and out of the tank by way of your floss/filter sock, and also removing co2.

My advice would be to try and keep a good flow to where all is happy.

You could try pointing the powerhead in a different direction, and turning the return down, if you have a powerhead you don’t need the return up that much.

I think you might find once the powerhead has been off for a while, the fish will go back to what they were doing, probably only coming out because something different was going on in the tank.

Feeding more could help, more food equals more energy also my clowns seem to come out more when the lights are mainly white, blues seem to get them to hide a bit more.

ashleyberg · Sep 27, 2021

jfoahs04 said:
Do you turn the powerhead off when you feed? If you do, your fish could be responding to that (thinking its feeding time).

I have a hard time imagining you have too much flow. I have the same tank, running the stock pump and a Nero 3 powerhead that peaks at just over 1,000 gph (about 30%). Prior to this, I was running a Current USA eFlux wavemaker at 100% (660ish gph). So 265gph should be a non-issue for the fish. I have a tailspot blenny and a small clown. Neither struggle with the flow and cruise around the tank, but both are most active when I shut it off to feed because they know what's coming. Your coral shouldn't have issues either unless it's pointed right at some of your nearby hammers. I have all sorts of softies and easy LPS and I only ever moved a frogspawn that didn't love being right in the flow (it's fine now).

Before pulling the powerhead altogether, I'd experiment with changing where it's pointed. You could turn it towards the surface a bit more, or point it at a side or back wall to "diffuse" the flow. You could also try keeping it off for a block of time. If you did remove it, the Siccee should be enough to move water and keep surface agitation adequate (so long as one nozzle is pointed at the surface) to keep the coral you have. But if you want anything more advanced, you'll want to have a bit more flow.

edit to add - this is my EVO with the powerhead running at 1,000gph pointed straight at the rear wall:

I don't turn the powerhead off when I feed, but I definitely understand why that would be a learned behavior if I did! The powerhead is still in the tank and running right now, I just wanted to see what people's thoughts were with the flow, as I do enjoy seeing the fish exploring more of the tank when it's off. But definitely want to keep doing what's best for the corals and everything else in the tank. Thanks for linking the vid - i'm about to watch it right now!

ashleyberg · Sep 27, 2021

Reef. said:
You don’t need to worry about the turnover rate, as long as the corals and fish as happy, turn over is mainly for sps.

Flow is good tho as it helps reduce the chances of getting cyano etc and helps kick up detritus into the water column and out of the tank by way of your floss/filter sock, and also removing co2.

My advice would be to try and keep a good flow to where all is happy.

You could try pointing the powerhead in a different direction, and turning the return down, if you have a powerhead you don’t need the return up that much.

I think you might find once the powerhead has been off for a while, the fish will go back to what they were doing, probably only coming out because something different was going on in the tank.

Feeding more could help, more food equals more energy also my clowns seem to come out more when the lights are mainly white, blues seem to get them to hide a bit more.

The point you made about the fish coming out because something is different in the tank, then going back to what they usually do is a great point to consider. I have the powerhead on right now, but i'll experiment tonight and leave it off for a couple hours and watch to see if they settle back into their areas. Luckily my tank is underneath my tv, so I get to watch them all night