To Bar or not to Bar

[Jellopuddinpop]

I like your drawing @Jellopuddinpop

Now onto some some fluid dynamics, hopefully without getting to deep.
In your diagram above lets assume both canister filters are the same. They both use 1/2" ID hoses from the manufacturer.
A 1/2" hose has a cross section area of 0.19625 sq.in. (3.14*R2). Two 1/2" hoses would have a cross section area of 0.3925 sq.in.
If you "T" the two 1/2" hoses to a 3/4" pipe going up, The 3/4" pipe has a cross section area of 0.441563 sq.in.

So, as you can see, the single 3/4" pipe will offer a path of less resistance for the 2 filters than a single filter on it's own.

Path of least resistance... this is the part that needs to be better understood.

If the filter on the left stops working (assuming it is still full of water and the tank to filter return is still full of water...
The filter on the right will have a choice - try and push water backwards thru the 1/2" tube and into the filter full of water and mechanical filtration, or, go up the 3/4" pipe and out into the tank.

Generally speaking, the water output from the right filter is going to follow the path of least resistance and go up the 3/4" pipe and into the tank.

In designing the horizontal spray bar - it should be noted that the sum of all the spray bar holes should be equal to or greater than the cross section area of the 3/4" riser pipe. This way, the spray bar itself will not add resistance to the flow of water. Each horizontal pipe in the spray bar can be 1/2" pipe without drastically effecting water flow - assuming the above sentence if followed. 3/4" horizontal pipes would be my overall preference.

From what @GreggZ was saying it might just be a waste of energy to combine them in the first place, but this is good info to have. If the filters used .625" hose, using your formulas above, I would size up to 1" PVC, correct?

Even with identical filters (which I would need to get), they're still not going to have the same flow. The one pushing the reactor has a lot of fittings to contend with, and the one running the inline heater has... well... an inline heater. If we assume for a minute that one filter has more head pressure than the other, and thus less flow, what happens then?

Does the stronger filter push against the weaker one, restricting flow even more?

 

[Immortal1]

@Jellopuddinpop yes, two 5/8" hoses (0.625" or 0.30664 sq.in) should T into a 1" tube (0.785 sq.in.).
Regardless if the left filter has less flow than the right filter, the idea would be to present less restriction as the two water columns move down stream.

Yes, the stronger filter could push against the weaker filter, but, the downstream restriction is less. So, both filters should still flow their perspective amount of water into the T. Now, if the T was 5/8" in all directions such that the riser was also 5/8" then there would be an opportunity for the stronger filter to restrict the flow of the weaker filter.

 

[OmidNiav]

I switched to spray bars on both my 40 breeders. I think I have more uniform flow when it comes to CO2 but don't have any evidence that it helps with better growth at this point. I don't think I would want to go back to a lily pipe in the future.

My two issues with the spray bar is that the holes closest to the source send stronger flow and also after restarting the filter I get a bunch of junk from all the holes into the tank since I can't just hold something in front of all the holds to catch the debris.

On another note, my DIY spray bar has holes that shoot water at different strengths. Although I made sure the holes are the same size. I think there is some plastic stuck on the inside that I cannot get out.

 

[Jellopuddinpop]

I switched to spray bars on both my 40 breeders. I think I have more uniform flow when it comes to CO2 but don't have any evidence that it helps with better growth at this point. I don't think I would want to go back to a lily pipe in the future.

My two issues with the spray bar is that the holes closest to the source send stronger flow and also after restarting the filter I get a bunch of junk from all the holes into the tank since I can't just hold something in front of all the holds to catch the debris.

On another note, my DIY spray bar has holes that shoot water at different strengths. Although I made sure the holes are the same size. I think there is some plastic stuck on the inside that I cannot get out.

I wonder if something like this would help?

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

McMaster-Carr

McMaster-Carr is the complete source for your plant with over 595,000 products. 98% of products ordered ship from stock and deliver same or next day.

www.mcmaster.com

 

[MrMuggles]

On another note, my DIY spray bar has holes that shoot water at different strengths. Although I made sure the holes are the same size. I think there is some plastic stuck on the inside that I cannot get out.

if the Furthest out holes are pushing less it is normal, has to do with distance from the water source, and fluid dymanics.

If you instead make spray "loops", where there's no single endpoint and the spray apparatus creates a complete & connected loop, the pressure remains more uniform at all the outputs.

 

[MrMuggles]

On another note, my DIY spray bar has holes that shoot water at different strengths. Although I made sure the holes are the same size. I think there is some plastic stuck on the inside that I cannot get out.

if you made these with a drill bit, you can usually fix it by running the drill in there again and wiggling the bit around to grab those leftovers. Then rinse out the entire spray bar a couple times to get the bits out.

 

[OmidNiav]

if you made these with a drill bit, you can usually fix it by running the drill in there again and wiggling the bit around to grab those leftovers. Then rinse out the entire spray bar a couple times to get the bits out.

I tried that but still have small bits of plastic stuck in there. I might need to get a small disk to clear those.

 

[Jellopuddinpop]

I tried that but still have small bits of plastic stuck in there. I might need to get a small disk to clear those.

Did you check out the McMaster links above? Those are meant to clear hanging burrs from inside tubes.

 

[MrMuggles]

Less than one week since switching to spray loops from high jet return nozzles, both flora and fauna are showing dramatic impact:
1. plants immediately started to grow taller downstream from the old jets
2. koi angel pair spawned for the first time (they are terrible at it but hey cool for trying)
3. all fish species more social and exploratory, due to reduced whirlpool

Result speaks for itself!

 

[Art]

Why do you think you're seeing the benefits? Is it the additional or more uniform flow?

 

[MrMuggles]

Why do you think you're seeing the benefits? Is it the additional or more uniform flow?

I think more uniform flow is the primary win here. A good portion of the spouts are below the halfway point in my tank now.

Center overflows + deep tank and high pressure nozzles and short loclines, I had crazy whirlpools. Dead zones in the lower rear. This return plumbing came with my tank, really it was designed for reefers.

The flow was very restricted by old loc lines and nozzles, I had to turn my return pump down significantly after installing the new system. So its also a win for power consumption and pump longevity.