Water Flow/Filtration Question (DIY)

[A3M0N]

I am a tinkerer. I like to make simple things if I can, I don't mind reinventing the wheel, it's fun sometimes. This filter, for example, is made of 1/2in PVC and is air powered. The inlet is on the left side, it goes down under the substrate and across to the uplift tube. The blue line may look a little wonky, but it's just to show the outlet is aimed at the front left corner of the tank, it's not actually aimed at the bottom corner. 

Most outlets and inlets are close to each other on the same side of the tank, does that result in better circulation that what I have made? I'm looking to possibly remake this filter, one for better flow, two because I made an oopsie when building it and it ended up too short. The pipe across the substrate is too close to the surface, rather than at the bottom of the tank, so it gets in the way of planting and hardscape. 

Would it flow/circulate better to have the inlet/outlet at the back right corner, aimed to the left corner? And the CO2 diffuser should be at the opposite end as the filter? Would 3/4in PVC be a better size? How about a spray bar outlet, what do you gain with a spray bar?

This is only a 10-gallon tank with small fish, I don't think I need a lot of power, but do want it to a good job circulating. I'd like to keep it air powered for simplicity, and I don't like the idea of filtration that could not restart or overflow in case of a power outage. 

[nabokovfan87]

This is an idea of your flow path right now:



Having a spraybar across the top would give you that even flow across the entire length of the tank.  Ultimately, a spraybar is one of the best ways to have great circulation.  Having the intake on or near the spraybar will best enhance that output flow when using a spraybar.  Water will circulate across the water surface, down the glass, back towards the output and then the intake takes in that water.  It's one oval / circulation path and that is going to reduce a lot of deadspots.

 

On 12/19/2022 at 2:01 PM, A3M0N said:

Would it flow/circulate better to have the inlet/outlet at the back right corner, aimed to the left corner? And the CO2 diffuser should be at the opposite end as the filter? Would 3/4in PVC be a better size? How about a spray bar outlet, what do you gain with a spray bar?

If you're using a single direct output, aim it diagonally across the longest part of the tank.  If your output is back right, aim it towards the front left and use lock line / duck bill outputs to spread it out, if possible.

[A3M0N]

On 12/19/2022 at 10:15 PM, nabokovfan87 said:

This is an idea of your flow path right now:

Yes, pretty much. The return flow is actually through a pipe under the substrate, so I don't think the lower level gets much if any flow. Is there any trick to visualize water flow? Like food coloring, would that be toxic to the fish? 

The output is aimed diagonally from back right to front left, and the intake is kind of in the middle of the left side. 

I may play with the idea of a spray bar at the top of the right side, and the uplift intake be in the middle(ish) below the spray bar. Time to scrounge for scrap PVC! 

Edited December 20, 2022 by A3M0N

[nabokovfan87]

On 12/19/2022 at 8:34 PM, A3M0N said:

Is there any trick to visualize water flow? Like food coloring, would that be toxic to the fish? 

Something like baking soda is used to raise PH, small amount might work. You could also use Ich-X.

On 12/19/2022 at 8:34 PM, A3M0N said:

The output is aimed diagonally from back right to front left, and the intake is kind of in the middle of the left side. 

Sounds good. I use a prefilter sponge, a spraybar kit, and a pumphead to have added circulation in my CO2 tank.

I'll try to snag a picture for you tomorrow.

[A3M0N]

@Pepere yeah, I tried an experiment today. I made a little spray bar and it worked, but water more just trickled instead of flowed out. And it was super noisy. I'll just plan to adjust my current setup to intake and output from the same end, hopefully that will create some circular flow. I may upsize to 3/4 in, but I figure a bigger pipe may flow more water but will be slower and not reach as far. My air pump also isn't super powerful, so I may be at the limit of what my current equipment can achieve.