Get In The Flow!

[aether.ed]

Hello all.
 
I recently got into a discussion with some one on here that has really got me thinking about water movement and filter/powerhead, direction, speed, angles, diverting flow etc. I know every set up will require different flow rates and head angles to suit the species and tank size but im really interested to know how and why everyone does theirs and what species you keep that cause you to do it in this way. This is something that is often overlooked and as far as i can find there is very little info out there, some site may say "this fish likes fast flowing water" but is that a fast direct flow along the surface? Through the middle? or just a brisk diverted current along the glass?  
 
Things like heavy filtration on an slow water movement loving fish set up, how do you angle your filters/heads to maximise filtration but minimise water movement? do you angle your heads to the surface, mid or bottom to get your desired flow? or how you aim the flow towards the glass or take the flow straight or diagonal along the tank and use plants to diffuse the current?
 
Or likewise the angles and positions you use for fast water loving fish?
 
Or the interesting one is any people keeping fast water fish and slow water fish together, how do you use powerheads and obstructions to keep certain part or your tank flowing fast and others gentle as pond? How about Circulation? do you go round in a whirlpool horizontally or go for the washing machine style movement on a virticle plane? Why? How?
 
The reason being, I was advising someone (who i shall call mr. powerhead) on congo tetras but his tank is set up for more fast flowing loving fish. However he has extremely generous tank dimensions and a multitude of filters and powerheads to play with which makes me think if hes clever about it, it could entirely work. Im just now curious as to how he'll do it and also curious about how you lot do it and why?
 
It will also be a great opportunity to share your set up and fish species with everyone and may become a great tool for others that may be worried about their set up. The classic example is the hillstream loach, i never see this fish kept correctly, always in slow flowing tanks with goldfish and fake plants obscuring any water flow. Might clear things up for people who dont have much luck with a particular species or not much luck at all. Also the opportunity to maybe correct mistakes that may be happening that you dont know about. Maybe you are one of those people that keep hillstream loach with goldfish in a simple out the box set up, wouldn't you love to learn how to let those fish thrive?!  
 
I'll get the ball rolling, i'll be brief and do it with a diagram as ive already wasted enough of your time with my essay here, haha.
 
African riverine species, Size 5x2x2 Species, congo tetra, synodontis euptera, elephantnose, mbu puffer, butterfly, brown knife, ctenopoma and kribensis. Water movement and filters: 2 x fluval 405 and a eheim 400 air pump. Aim: slow moving lazy congo forest biotope, slow as possible current but still maximising water movement for filtration as i have quite a bioload and feeding regime.
 

There are plants to divert the flow around the left hand outlet so it doesnt hit the glass with much force and the outlets are 1/2 an inch from the surface, straight and flat at 90degress. With the generous amount of wood in the tank the flow is minimal in places, only along the back is there any significant flow. 
 
I think ive got it right and the fish have thrived for years but any criticisms and advice is welcome as is the aim of this post! Maybe i need more movement around the center and bottom? Ive never really worried about dead spots but should I?
 
Thats enough typing, i'll leave it to you, no need for a fancy shmancy diagram I could have written about it but the post would have gone on longer than it already has!
 
Sorry about the novel, fire away!
 
Ed

 

[techen]

Can I ask why use air pumps when you have plants? Decreasing the amount of CO2 needed for plant growth?

 

[aether.ed]

I dont have that many plants, the air pump is for surface movement and agitation. Because of the slow flow it gets a bit stagnant and filmy around the bunched up vallis in the left corner. I have quite slow surface movement, and not enough plants to make a difference in oxygen levels. Its incredibly low light my tank, its not about the plants, did have tons but they just took up space, just wanted the anubias to enhance the african vibe and a bit of vallis for the ctenopoma and butterfly to hang in. 
 
I may be wrong, and frequently am but i doubt 3 vallis plants and 5 small anubias with very little light would do much oxygen wise in a 5ft tank with 40ish large fish. 
 
But what do i know eh? For all i know a single anubias leaf may provide as much oxygen as an air pump! haha

 

[Geoff-]

If you want to slow down water movement then a spray bar is the easiest method.  Put it just under the waterline and angle it upwards slightly so it ripples the surface and this will help with oxygen exchange as well.  If you did this with one of the filters (the left rear one, have it pointing forward) and left the other to generate circulation along the back wall then you should get the result you want.
 
I run a 3ft planted tank (with canister filter) and it doesn't oxygenate enough with just the plants.  Fish will always consume more oxygen than plants generate at typical stocking levels.  My fish end up with rapid breathing unless I have an airstone in there as well.  It's a relatively new tank so I'm still experimenting.  My other tank is much more heavily stocked but don't have the same issue, it's an aqua one 620 and the wet/dry filter system seems to oxygenate the water quite effectively without additional help.

 

[aether.ed]

Water movement isnt realy an issue in my tank, no problems or issues at all, its fine for the fish i keep. Me and the fish are more than happy with the air pump for surface agitation. But sure, any advice will be noted and may be acted upon.

My tank has been going strong with all the same fish for over 4 years now with not a single death and I keep the notoriously fussy and difficult elephant nose fish so i must be doing something right! If there is anything i could do to more closely match their natural habitat then great!

But the purpose of this thread is because I was curious to know how and why everyone does it the way they do? Do you go for linear or a turbulent flow for the species you keep? stuff like that. I have my reason for having it set up like this, what are yours?

Tell me about your tanks, do you aim for a circular flow around the surface or through the depth of the tank? Or does your water not go round in a circle at all, in a more linear fasion like a river or a stream? If so why? what fish do you keep that require these conditions?

I want to know different flow/circulation set ups for different types of tanks and species as there is no or very little info out there other than fast or slow flow, theres nothing about direction or angles.