Water flow in the planted aquarium?

Cherry

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I tried that ,but it was too big.I have ordered one of those high power diffusers from aqua essentials,so will try that thanks.It takes a while to learn the terms! Took me ages to find what a reactor was - turns out the filter will be fine! Looked at that in line reactor,-seems a great idea ,but think i will have to wait a bit as I have already spent loads - also cant work out how to fit it on my fluval filter as it has ribbed piping rather than usual.- bearing in mind what you said about flow.
I will go and speak to my Guru at Maidenhead aqatics - better still I will until you have tried it!:)
 

Cherry

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btw - I have now got the high powered diffuser,have put it under my input pipe of my bigger filter and its working really well - the bubbles are really tiny and they go up the pipe a treat! ;)
 

ADA

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Quick question in the same field, I've just bought a 240L optiwhite, got 2 filters, I know it's best to have the outlet next to the inlet for a circular flow but would you put both sets side by side on the same end or put the two sets on opposite corners of the tank? I was thinking same end otherwise one filter would just feed the other?

Steve
 

ceg4048

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Hello,
From a flow/distribution perspective, place the filter inlet tubes wherever you want. They do not contribute much to the shape of the flow field. The placement and orientation of the outlets are much more important. THEY must be on the same side pointing in the same direction, otherwise the risk of energy cancellation and incoherent flow is high. When multiple outlets work together they multiply the flow energy and contribute to uniform flow.

Cheers,
 
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I am thinking of getting a (small) submersed pump hook up a spray bar and place this on the bottom of the tank all the way in the back facing the holes (output) up, this to get more flow to the plants that are placed far back, I hope this upward flow creates suction and therefor getting a better distribution to the back.
Any thoughts on this?
 

ceg4048

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Hi Martin,
This could work, depending on obstacles along the back wall. This should help pull flow across the bottom, but if it's too strong it may disrupt the horizontal flow across the top from the main spraybar.

Cheers,
 
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Hi Martin,
This could work, depending on obstacles along the back wall. This should help pull flow across the bottom, but if it's too strong it may disrupt the horizontal flow across the top from the main spraybar.

Cheers,
I left about 5cm free from the back when planting, but plants are stubborn ;)..I guess it will be OK. My tank is 300liter, I was thinking to use a 500-1000 liter/hour pump
 

Luis Batista

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Hi Steve,
Here is a photo of a sample installation. You might just be able to make out the back glass. There are actually 3 spraybars. Two of them are ganged together on the left side with an inch long piece of tubing. I was too cheap to buy a 4th for the right side. Remember this is a 6 footer. This is not a very sophisticated installation at all. They are just mounted on the back with suckers and just joined to the filter outlet tube. I don't even use the shepherds crook, no need and better flexibility. Now, Fred Flintstone and Barney Rubble would have done it this way so I'm not particularly proud of it's lack of modern aesthetic appeal but it works. The holes in the bars point straight out - horizontal towards the front, maybe even slightly upwards. I previously had HC in the foreground which used to just decay when I used the £40 lily pipes. Subsequently, after spraybar installation, huge mats of it would detach from the substrate due to the buoyancy from pearling, which actually became annoying.
8396954239_ff17a4e4ab_c.jpg


This shot shows the bars more closely and shows the orientation of the holes. I found a much better behaved ground cover plant (P. helferi) and it also benefits from this simple configuration.
8396953793_920569535d_c.jpg


I use two inline diffusers and two filters, one is a Cal Aqua and the other an AM1000. Ideally, mount the spraybar centrally but you can do as I did and join two bars together. This gives you better coverage and lowers the exit velocity at each hole because there are more holes. On my setup there are a few gaps, like at the two far ends of course and a foot or so in the middle. No big deal.

Remember, if they look too ugly you can mount them way up at the waterline so that you hardly notice them. Of course, real aquascapers would never even consider such a cheesy setup, but hey, it works. Just you try growing a 6 foot mat of HC 2 feet underwater. Not even remotely easy. :wideyed: This give you the best chance. Anyway, I've completed a self hypnosis course and now I tell myself "what spraybars?" :p

Cheers,


Hi ceg

do you think that a Tetratec EX700, 700L/H, could be strong enought something like this but shorter, my tank is 100 cm.
Because of your talk about encrease flow on one of my posts, i´m thinking of buying a pvc pipe, drill some holes on it and try it...

Cheers
 

ceg4048

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Hi Luis,
It\s very difficult to predict. The length of the pipe, it's diameter, filter tubing length, the hole sizes and number of holes as well as how far the pump head sits below the water surface all affect the ability of the pump to deliver adequate flow. It's a good idea you mention to just get some cheap plastic pipes and see how it goes.

Cheers,
 

Luis Batista

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Hi Luis,
It\s very difficult to predict. The length of the pipe, it's diameter, filter tubing length, the hole sizes and number of holes as well as how far the pump head sits below the water surface all affect the ability of the pump to deliver adequate flow. It's a good idea you mention to just get some cheap plastic pipes and see how it goes.

Cheers,
Will give it a try.
Just one more thing.
In theory if i put a smaller diameter of pipe, it will compensate the larger length right?
It will create more pressure to the last holes...
Being the tank 100 cm it need about what? 80 cm of pipe is enough to the back wall?

Once again, thanks for all your advices...

Best regards,

Luis batista

Enviado através da ponta dos meus dedos!
 

foxfish

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You are asking very difficult questions as it really depends on mutable factors!
If you could set up an experiment in the bath or paddling pool you would see the effects of ... pipe length, how bends effect flow, how height effects flow & how pipe restrictions effects flow.
Some factors can be very noticeable with the naked eye but try filling a bucket & timing the period it takes to fill.
Most of the pumps we use have low power consumption & plastic impellers & in turn are effected by small changes that restrict the flow.
 

ceg4048

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The idea is to get as much mass flow rate as possible. Reducing pipe diameter severely reduces mass flow rate and will not compensate for anything.

Think about your garden hose when you restrict the outlet orifice size. The spray comes out faster but much less mass of water squirts out of the orifice.

80 cm sounds fine, but in the end, you'll have to look at your installation and see how much room you'll need for connections and so forth. The PVC is very cheap so get long lengths and experiment in order to find the answers based on your configuration.

Cheers,
 

Luis Batista

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You are asking very difficult questions as it really depends on mutable factors!
If you could set up an experiment in the bath or paddling pool you would see the effects of ... pipe length, how bends effect flow, how height effects flow & how pipe restrictions effects flow.
Some factors can be very noticeable with the naked eye but try filling a bucket & timing the period it takes to fill.
Most of the pumps we use have low power consumption & plastic impellers & in turn are effected by small changes that restrict the flow.

Hi
i have a circulation pump of 600l/h but im thinking of using my tetratec filter insted because of the inline diffusor

cheers
 

Luis Batista

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The idea is to get as much mass flow rate as possible. Reducing pipe diameter severely reduces mass flow rate and will not compensate for anything.

Think about your garden hose when you restrict the outlet orifice size. The spray comes out faster but much less mass of water squirts out of the orifice.

80 cm sounds fine, but in the end, you'll have to look at your installation and see how much room you'll need for connections and so forth. The PVC is very cheap so get long lengths and experiment in order to find the answers based on your configuration.

Cheers,


will study well this stuff
Perhaps the pump boosts a pvc pipe on half the back wall and the filter, who have the inline diffusor, the other half. maybe the flow of the 2 together can spread the gas evenly on all tank...

thanks
 

Luis Batista

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Just another question.
Does this system with a spraybar on the back wall, the intake will work ok? Does the Walter of the other side of the intake can go to the intake pipe?

Enviado através da ponta dos meus dedos!
 

Jason Blake

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1 Sep 2014
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Hi,

I think after reading this thread that I just about understand the flow and distribution needed in a plant aquarium, however I still I cannot really workout how to implement adaquate flow and distribution in my aquarium. Fluid dynamics was never really my strong point. I think the biggest problem I have is that my aquarium is hexagonal in shape and therefore I think that the shape alone my inhibit such a goal. I have come up with three possible solutions and I would really appreciate some construction advice and recommendations.

Setup 1 - This setup uses three spray bars along the three back walls of the aquarium. Remembering what Ceg has said about uniform flow and ensuring that it is additive and not subtractive, I am not sure if because of the angles of the two outer walls if they would cancel out the flow from the spray bar at the back facing forwards.

AD5pxu.jpg

Setup 2 - In the setup the spray bars are on the two side walls and as above I am not sure if the angles will cancel each other out.

xcN1ny.jpg

Setup 3 - In this setup I would put the spray the whole length of the tank. I think out of all three this will give me the best flow and distribution as there will be no converging angles. However I am concerned as to whether or not the flow would come up the back of the aquarium to complete the full flow circle? I am not too bothered about the bar being in the middle of the aquarium as far as asthetics as I believe one way or another this can be sorted. I am only concerned about acheiving optimal flow.
n66fni.jpg

To create the flow I will be using an external cannister filter with an inline diffuser. This filter has varible flow rates starting at 300 l/hr upto 1610 l/hr. I have a 60 Litre aquarium, extra flow pumps can be used if necessary.

I would really appeciate some advice.

Thanks.
 

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