Water Current and Tetras

[Blaha]

Water flow rate is a hard to grasp concept for me. How much is too much? too little? It's not really a thing I can measure so it makes me wonder.

I know to a point that flow rate is subjective and what I see as too much or too little may be different than what you think. I have a 29 G and a sponge filter with the USB nano pump. The water is almost a stand still with that and the fish weren't interested in the food just sitting there, so I added an ACO power head but that was way too much. after some trial and error I landed at facing the power head right at a decoration about 1.5 inches away from the output. That weakened it a lot, but the tetras still don't necessarily like it I think. They often times hide in the plants which is a sign of stress and exhaustion. It also wants to suck all my floating plants into the one side and tangle them with my lily pads, which also tangle in each other.
I want to wait for the new ACO pump because it is supposed to be 1.9L/m compared to the nano 0.6L/m but I am at an impasse and don't know what to do in the meantime. This flow issue has been an internal debate for a few months now and I just don't know about flow rates very much and what's good, what's bad, etc. I suppose it's a good amount of anxiety over potentially nothing. I'm also sure my anxieties about waiting for this new pump are far less than that of the ACO team and I'm not complaining about something outside of everyone's control, I'll wait patiently.

Anyone else out there with tetras(or other nanos) and more experience with creating a proper current in their tanks?  I've always used basic stuff from chain stores until about 6 months ago when I went to sponge filters and live plants and all that. I love the hobby more than ever, it's way better living conditions for the fish and more enjoyable as the viewer, but it's hard to be un-knowledgeable again in this new level of complexity and more variables to think about in my mini environment.

[GameCzar]

I haven't quite figured out how to dial back the power of the power head, I've used it to great success cylcing/cleaning a fishless tank, but the flow is impressive.    To be fair, we have smaller tanks. 
 

[Blaha]

Powerhead is for sure not a misnomer. I think in a smaller-medium sized tank it would great to put the powerhead o the top of a sponge filter, and then run a line from the output to above the water surface and run it across the back of the tank with a slit cut in it so that you have the incredible filtration it can provide and a waterfall across the entire back of the tank. That wouldn't fit in my current set up but on maybe on another tank someday...

Or someone else can see this and take that idea for themselves

[Randall from Texas]

I put a large intake sponge on my ACO power head. It dials the flow back after the filter gets good and full of bacteria. I asked on a live stream and Cory said the small prefilter would fit on it to further reduce the flow.

 

Edit: also I have tetras that like to get into the flow when the food is there.

Edited January 7, 2022 by Randall from Texas
Note about my tetras

[Blaha]

They definitely do enjoy eating more when the food is flowing, and I do have a small sponge on my intake. Its is incredible at filtration. I would love flow somewhere between the sponge filter and the powerhead.

I'm glad to hear they are okay living in that flow. It's all so new to me

[Blaha]

I had turned off the powerhead this morning to see how they feel after a few days while I observe them, and the general tank. It's the only way to really learn. Watch the fish, test the water, monitor algae and plants, etc. after making a change. 
The only main observations so far, after like 12 hours is that the floating plants and lily pads have spread out more across the surface, and the tetras are swimming around the tank in the school instead swimming in place toward the flow in the center of the tank

[Atitagain]

To me being aware of your flow is very important for health of fish and tank. Some fish like high some low flow keeping track of this helps with keeping stress levels low. Good current keeps debris of all kinds off the bottom sometimes good/ bad. I don’t keep any long fins or fish that are real sensitive. I have a 20G with pea puffers, only a small air stone and a small HOB so in my tanks that’s super slow but for someone who keeps betta that might still be way to much.

In a 75G African cichlid tank I need to keep debris (poo) off the bottom so I use: 2 canister filters, large ACO sponge filter, 10” bubble wand at right end, and a circulator on left end. IMO that’s a lot might even need to dial back but seems to be working well.

then in my tetra tank 125G I have canister filter, medium HOB, 8” bubble wand, small air stone, and a large ACO sponge filter with a power head on it pointing from back left to center front. This also crosses the flow started from the bubble wand. This tank has high flow up front and dead spaces/ low flow in back, purposely. When feeding most all fish (about 40-ish) know I start at right side drop a little then a big portion in center then everything flows to right where I have shrimp colony to capture left overs. Fish start in center hit the food, swim down steam hit again, then congregate hit floating food and pecking the ground.( fairly cool watch every day 😁) I also use this same current to make my vallisneria flow across the top of my tank and create a lot of movement within the planted section. Hope this pic makes sense.

shows in red the powerhead, Bubble wand, small bubble, and HOB the canister intake is right corner output is center pointing center/ right to cross with main flow/current. Current hits hanging roots and the large-ish rocks on bottom right to disperse and create (in theory that seems to be working) a dead space under hanging roots.

These are some of my thought process when it come to flow/ currents in my tanks.

 

Edited January 8, 2022 by Atitagain

[Blaha]

It took a few rereads to get it but I figured it out.
the tetra sounds like pretty high, or at least visibly noticeable flow. The tetras need to chase the food. That's the main thing I'm noticing with it off. They are going after the pellets but not the flake food as it drifts. They would chase the flake food as it got caught in the current though. I suppose if I need to choose between flow and floating plants I will go with flow for the fish.
In my 29G tank I have a Lg sponge filter with the USB nano pump, and a powerhead with a Med pre-filter sponge. To reduce the flow a bit the power head smashes into the barrel decoration and the flow gets dispersed a bit. Generally it goes across, and comes back on the top, a bit at the bottom. The sponge offers little to flow but adds surface agitation. I am not sure about the flow in the barrels, It's either pretty still because the conflicting directions or nuts. Not many things go in it, but since I have replaced my Val in the center with some Pennywort my Corys go in the barrels more. I just have no way of knowing the strength of the flow at any point besides the surface where plants get sucked right and when food gets pulled over to the barrels it only takes a few seconds to shoot back to the left.
I tried to make my drawing in the same way you made yours's with the barrels outlined in orange. I'm just a graphic designer and find it easier to drop something in Adobe Illustrator instead of trying to draw on my phone

[Randall from Texas]

On 1/8/2022 at 8:44 AM, Blaha said:

It took a few rereads to get it but I figured it out.
the tetra sounds like pretty high, or at least visibly noticeable flow. The tetras need to chase the food. That's the main thing I'm noticing with it off. They are going after the pellets but not the flake food as it drifts. They would chase the flake food as it got caught in the current though. I suppose if I need to choose between flow and floating plants I will go with flow for the fish.
In my 29G tank I have a Lg sponge filter with the USB nano pump, and a powerhead with a Med pre-filter sponge. To reduce the flow a bit the power head smashes into the barrel decoration and the flow gets dispersed a bit. Generally it goes across, and comes back on the top, a bit at the bottom. The sponge offers little to flow but adds surface agitation. I am not sure about the flow in the barrels, It's either pretty still because the conflicting directions or nuts. Not many things go in it, but since I have replaced my Val in the center with some Pennywort my Corys go in the barrels more. I just have no way of knowing the strength of the flow at any point besides the surface where plants get sucked right and when food gets pulled over to the barrels it only takes a few seconds to shoot back to the left.
I tried to make my drawing in the same way you made yours's with the barrels outlined in orange. I'm just a graphic designer and find it easier to drop something in Adobe Illustrator instead of trying to draw on my phone

This looks great. Once your plants fill in it will help break up the flow even more