# Flow In A Large Low Tech Tank



## James O (9 Jul 2014)

I'm a planner, and so like to cover all the angles befor I set sail

Project details so far are:

Large tank - 183x50x50 pending spousal approval, but definitely tightly in this 400l region

Low tech - I've been playing around with LC but I'm not really seeing much benifit between tanks with/without

Filtration - I'm going to run 2x Eheim 2217 with DIY prefilters.  Inflow at one end, outflow at the other.  

Scape - lavarock & redmoor heavily planted with various anubias, bolbotis, java ferns, moss and swords

Wildlife - a generous smattering of rainbows, denisonii barbs with a large otto & amano shrimp cleanup crew

Water flow is my present brain teaser.  As this is low tech I don't need CO2 tank levels of flow but I know I still need movement to keep detritus moving to the filters and to transport ferts around the tank etc.  I'm not planning to use the Eheims for flow, other than what a simple shepherds crook or similar can produce.  This will give me longer filter cleaning intervals as flow won't be reliant on filter output which obviously drops with buildup. 

My options as I see them are: pump attached to full length spraybar, or, powerheads (koralia etc)

What would you guys do?


----------



## Tim Harrison (9 Jul 2014)

What turnover will your filters give you James?


----------



## ourmanflint (9 Jul 2014)

I would try to create an even laminar flow from one end of the tank to the other, there's a new pump in market specifically for that. Can't remember its name though!


----------



## James O (9 Jul 2014)

Troi said:


> What turnover will your filters give you James?



In theory 1000lph each, so up to 2000lph total.  They are specced up to 600l tank each but I think that's optimistic and so two on a 400l tank is plenty.  I'll be using them 1/2 to 3/4 full of pan/pot scrubbers as I've found these allow plenty of biological filtering and great flow. This will be helped by the prefilter (aka open cell foam wrapped around the inlet) doing most of the mechanical filtration.[DOUBLEPOST=1404910280][/DOUBLEPOST]





ourmanflint said:


> I would try to create an even laminar flow from one end of the tank to the other, there's a new pump in market specifically for that. Can't remember its name though!



Is it that maxspect horizontal cylinder fan type contraption?  Might be a bit blowy for a planted tank as it's aimed at the marine market I believe?  Those balls being flung round the tank was impressive.  I wonder of they do a little one?


----------



## James O (9 Jul 2014)

Just looked here http://www.coralvue.com/maxspect-riptide-gyre-generator and they do.  Look at the product images.  Might be spendy though 

Is circular flow along the tank any different to the sort a full length spraybar creates?


----------



## sciencefiction (9 Jul 2014)

I'd personally have double that in filtration for that dimensions and size tank. Forget about whether it's co2 or non-co2 tank and aim at 8-10x in filtration. These two 2217 will barely cope with the tank once you stock it and feed it as per the size allowance, plus them slowing down before each cleaning and the small volumes those filters have.


----------



## James O (9 Jul 2014)

Really?!?  12l of filter medium won't be enough


----------



## Andy Thurston (9 Jul 2014)

James O said:


> Really?!?  12l of filter medium won't be enough


Thats what i thought. I would have said a planted tank would be fine with 12l of media. Flow doesn't really drop off with the 2217 either, even when its filthy and rammed full with media it only slows a bit. Make your hoses as short as possible this will give you much more flow. Long hoses restrict flow much more than lots of media.
I would think about more flow too, power heads supplying custom spray bars is easy and cheap but you do need to hide the pumps
Finally dennisonii are good jumpers, mine sometimes chase each other out of the water when sparring so heavy covers are advised

Ps i hope mrs o approves


----------



## James O (9 Jul 2014)

Mrs O is in full accord.  Mostly because I'll just have 1 tank rather than 4 in our lounge  Bargaining power 

Yes I'll need more flow.  A spraybar with a waveline or jebao 3000lph pump running at 60-70% would be enough but 2 or 3 koralia type heads give me more adjustment (aim and individual flow rates/patterns) depending on scape layout etc. I like the look of the new eheim heads....

But which way to go?  Both are about as expensive.  More powerheads means more flexibility.  Pump for spraybar would need to be hidden & cleaned but seems the standard. 

 I dunno.....any ideas?


----------



## sciencefiction (9 Jul 2014)

You can do it with 12l of media. Some people even do it without any filtration altogether. But it's another story what's optimum or what's best.


----------



## Kev_M (9 Jul 2014)

Yeah, perhaps it isn't optimal - though I don't see the problem - but to say two 2217s would "barely cope" with a stock on a tank that size is nonsense. As Big clown has pointed out, the flow doesn't drop off much on these filters, either.


----------



## Edvet (9 Jul 2014)

Btw, have a think about a sump, works like a charm, especially without CO2


----------



## James O (9 Jul 2014)

Kev_M said:


> Yeah, perhaps it isn't optimal - though I don't see the problem.



Blimey  How much filtration 'should' I have then?[DOUBLEPOST=1404932908][/DOUBLEPOST]





Edvet said:


> Btw, have a think about a sump, works like a charm, especially without CO2



Oh the very thought of a sump makes me warm and fluffy- I love the 'idea' of them   But I'm terrified of leakages   I've read up on durso, bean animal etc and the advantages are HUGE.  I fear leaks and the extra weight, on top of the 400kg of water, 50-60kg tank + stand.  I'm on the first floor


----------



## Kev_M (9 Jul 2014)

James O said:


> Blimey  How much filtration 'should' I have then?



I meant 'optimal' in the sense that any combination of filters with a larger capacity and a higher flow-rate would be better. I really don't see the problem. You're using two quality filters rated at 600 litres each. You're over-filtering. You can add more flow in the form of powerheads or whatever, but you absolutely won't _need_ more filtration than two 2217s on a tank that size. You just won't.


----------



## James O (9 Jul 2014)

I'm not actually using the filters for flow at all.  That's what I can't decide, powerheads or spraybar?  Filters are purely for filtering


----------



## NC10 (9 Jul 2014)

James O said:


> Oh the very thought of a sump makes me warm and fluffy- I love the 'idea' of them   But I'm terrified of leakages   I've read up on durso, bean animal etc and the advantages are HUGE.  I fear leaks and the extra weight, on top of the 400kg of water, 50-60kg tank + stand.  I'm on the first floor



Don't be afraid of leakages, if it's done right that is 

As far as weights concerned, the sump is normally only run at half capacity anyway (to cater for any water left in the weir should the return pump fail) so even a 100l sump will only be around 50/60 kg extra (plus the tank) Not much anyway in the grand scheme of things. Go for it.

Good luck with the build anyway, whichever way you decide to go


----------



## sciencefiction (9 Jul 2014)

Kev_M said:


> You're using two quality filters rated at 600 litres each. You're over-filtering.



Overfiltering? That's 2 filters, 600l/h each on a 450l tank, that's 2.67 the tank volume an hour. I think that's hugely underfiltered.

Edit: Oh, sorry, my bad, they are 2000l an hour between the two, so it's 4.44 times the tank volume an hour, still underfiltered in my opinion.


----------



## James O (9 Jul 2014)

But higher speed of flow across/through filter media doesn't equal better filtration. Possibly the opposite


----------



## NC10 (9 Jul 2014)

I've got 2x flow running through mine and to be honest it is spot on. I did actually want more when I was planning, probably 4x I originally had in my head, but due to head height I've lost near enough 1500lph off my pump. I'm heavily feeding I suppose (young discus & beefheart 5 times per day), but 15 minutes after feeding the water is back to normal, no small particles and clear again.

I think people might start confusing flow rate with the filtering rate. A slower flow through the filter is going to be a lot better than water flying through at speed IMO High flow is going to force far more bits through than one flowing slowly, obviously ending back in the tank eventually, possibly. The water is also in contact with the bio media for a lot longer. As long as the actual flow rate in the tank is strong enough and keeps everything in suspension, the filter will eventually pick it up no matter how slow it's rate is.


----------



## Kev_M (9 Jul 2014)

sciencefiction said:


> Overfiltering? That's 2 filters, 600l/h each on a 450l tank, that's 2.67 the tank volume an hour. I think that's hugely underfiltered.
> 
> Edit: Oh, sorry, my bad, they are 2000l an hour between the two, so it's 4.44 times the tank volume an hour, still underfiltered in my opinion.



It's not, though. I've had two 2217s on a 450 litre tank that was packed full of 4" mbuna. I had roughly 40 of them in there and they are messy fish. People say you should aim for 10x turnover but that is in part due to certain brands of filters only really supplying 50% of stated flow. I've run a lot of practical tests with external filters. On this 450 litre mbuna tank, I went through an FX6 (rated for 1500 litre tanks, but given your own criteria one of these wouldn't be fit to filter a 450 litre tank), two Tetratec EX1200s and two Eheim 2217s. All of them performed well but the FX6 was the worst out of them (despite having the best actual flow-rate). I put this down to the limited capacity compared to the other combinations. I found a couple of litres of a high quality sintered glass bio-media divided between the two filters was enough to deal with the bioload. That then left me with 10 litres of mechanical filtration. My water was crystal clear, every parameter was as it should be, and for extra flow I just used wavemakers.

Sorry for derailing your thread, James. To take it back to the topic I'd recommend the Tunze Turbelle range for water-movement. Like your 2217s, they're energy efficient and no fuss.


----------



## NC10 (10 Jul 2014)

Kev_M said:


> People say you should aim for 10x turnover but that is in part due to certain brands of filters only really supplying 50% of stated flow.



Regardless of what brand, actual flow rate, or expected flow rate, the 10x "rule" still comes into play.

It's up to individuals to test what their own flow rate is, after taking into account head height, how much media etc etc. I know not many people will actually do it, but it's pretty easy to put a jug under the outlet and time how long it takes to reach a litre, as you probably know from your tests. I'm guessing a lot of people will be shocked as well 

I'm pretty sure though, that someone didn't come to the conclusion that 5x was the optimum flow and then said, just double it because companies lie by 50% how much is actually being turned over


----------



## James O (10 Jul 2014)

I believe 10x thing has nothing to do with filter capacity.  It's purely a theoretical figure  used to make sure there is more than adequate flow around the tank (allowing for media, head and pipework losses), ensuring plants receive maximum benefits from CO2 and probable EI dosing.  Flow describes the delivery/movement of (possibly CO2/fert bearing) water around the tank.

I'm pretty sure for example, that Sanj and Alistair aren't getting 17,000lph and 14,000lph turnover via filtration[DOUBLEPOST=1404949768][/DOUBLEPOST]





Kev_M said:


> ..........for extra flow I just used wavemakers.
> 
> Sorry for derailing your thread, James. To take it back to the topic I'd recommend the Tunze Turbelle range for water-movement. Like your 2217s, they're energy efficient and no fuss.



Wavemakers (sorry been calling them powerheads ) seem to be the more practical solution as compared to a pump and spraybar.  Btw no need for apologies, constructive conversation with practical experience is always valuable 

So based on the fact that the up to 2000lph from the filters is _not _being taken as turnover rate, 2 or 3 wavemakers strategically positioned should be fine?


----------



## Kev_M (10 Jul 2014)

NC10 said:


> I'm pretty sure though, that someone didn't come to the conclusion that 5x was the optimum flow and then said, just double it because companies lie by 50% how much is actually being turned over



Actually, if you have a read about on here and other forums you'll find many posts from people saying exactly that. The other common one being to buy a filter that is rated for tanks twice the size of your own.

All of this is besides the point of course - which was two 2217s will be plenty on James' tank. Well, that and the fact he's asking for advice about flow (inside and around the tank).


----------



## NC10 (10 Jul 2014)

Kev_M said:


> Actually, if you have a read about on here and other forums you'll find many posts from people saying exactly that. The other common one being to buy a filter that is rated for tanks twice the size of your own.



I've never come across that but I'll keep my eye out for it now, see what they're saying. Do you have any links? I'd like to know how they were, or are, trying to deliver their 10x. Just to see if that plays a part.

It should go without saying really that you over do the filter slightly, you can always wind it back. If people are naive enough to not realise that manufacturers calculate straight from the pump without head or media, then so be it 



Kev_M said:


> All of this is besides the point of course - which was two 2217s will be plenty on James' tank.



It would as far as water filtering is concerned, but with additional tank flow via pumps and powerheads etc



James O said:


> I believe 10x thing has nothing to do with filter capacity.  It's purely a theoretical figure  used to make sure there is more than adequate flow around the tank (allowing for media, head and pipework losses), ensuring plants receive maximum benefits from CO2 and probable EI dosing.  Flow describes the delivery/movement of (possibly CO2/fert bearing) water around the tank.
> 
> I'm pretty sure for example, that Sanj and Alistair aren't getting 17,000lph and 14,000lph turnover via filtration


----------



## Edvet (10 Jul 2014)

James O said:


> 2 or 3 wavemakers strategically positioned should be fine


 I use two koralia's (6000 and 12000) for extra flow in my large tank, paired with a 2-3000 liter eheim (wich just puts water through a sock) and app1500-2000 lit through the sump. I still was going to craft a  diy spraybar to improve flow. Problem even in a large tank is the flowprofile of a circulation pump, to localized. In hindsight it would have probably been better to buy 10 small pumps and put them all in the back (like a spraybar), to get a wider softer flow. I pointed the big ones to the surface partially to soften the flow, i could lay the large plants "flat" easily had i wanted.


----------



## sciencefiction (10 Jul 2014)

Kev_M said:


> On this 450 litre mbuna tank, I went through an FX6 (rated for 1500 litre tanks, but given your own criteria one of these wouldn't be fit to filter a 450 litre tank),


 
I am simply recommending what consistently works for me. I don't have problems with plants when I have lesser filtration and flow, neither do I have any water clarity problems in any planted tank.  I have mostly problems with fish when my plants aren't growing up to expectations if the tank is averagely filtered and that's without ever detecting ammonia/nitrites on a test. Plants when not growing well produce waste and a lot of it.
 It just seems with average filtration sometimes tanks can be unstable but one can be lucky.  Plus any tiny ammonia rise triggers algae blooms even if it's in its non toxic form like NH4. So I try to avoid that by overfiltering which can be expensive if ones idea of filtration is Eheims.
So yes, in a 450l tank I'd have two FX6 rated 2130 each, maybe more  But in a planted tank I'd probably opt for filters with spraybars that I can place along the entire length for circular flow.


----------



## James O (10 Jul 2014)

sciencefiction said:


> It just seems with average filtration sometimes tanks can be unstable but one can be lucky.



Or just maybe, perhaps there are some tank owners who _are _fully competent  



sciencefiction said:


> So I try to avoid that by overfiltering which can be expensive if ones idea of filtration is Eheims.



So you've just called me and every other member that uses eheim filtration stupid without providing any credible evidence - thanks for that.  What's _your_ issue with eheim?  It 'seems' to be clouding reasonable discussion, especially in light of this statement



sciencefiction said:


> So yes, in a 450l tank I'd have two FX6 rated 2130 each, maybe more



FX6 has equal filtration capacity to the 2217.  The _only _difference is flow through the filter media.  It simply cannot hold more filter bacteria than the eheim so it's only trick is more lph over/through the media.  If speed of passage through media always equals better filtration then why do so many companies including eheim, fluval and ADA (to name a few) make comparatively low flow filters?

Baring in mind I was only talking about flow because I'm separating flow from filtration (I'm not taking filter flow into account at all) in a heavily planted low tech tank - spraybar or wavemakers for flow, Eheims for filtration with 4x turnover - why is an FX6 better?


----------



## sciencefiction (10 Jul 2014)

James O said:


> So you've just called me and every other member that uses eheim filtration stupid without providing any credible evidence - thanks for that.  What's your issue with eheim?  It 'seems' to be clouding reasonable discussion, especially in light of this statement



Sorry James but when did I call anyone stupid? I have an Eheim filter, it works fine. They just can be expensive to achieve the same thing in a large tank.
I don't understand why are you feeling offended by me expressing an opinion that two 2217s are not optimal filtration for the size of the tank in question?[DOUBLEPOST=1404997909][/DOUBLEPOST]





James O said:


> Eheims for filtration with 4x turnover - why is an FX6 better?


 
I really don't know. I haven't at all been comparing filter brands here. You are. I haven't used either FX5 or FX6 personally.[DOUBLEPOST=1404998086][/DOUBLEPOST]





James O said:


> Baring in mind I was only talking about flow because I'm separating flow from filtration


 
Well if that's your aim, then two All Pond Solutions 2000 EX will do a great job for fraction of the price


----------



## sciencefiction (10 Jul 2014)

James O said:


> Or just maybe, perhaps there are some tank owners who are fully competent



Maybe.
I apologize for my incompetent opinion. Please ignore my posts.


----------



## James O (10 Jul 2014)

And back to the original question, in my very first post, at the top of the first page...



James O said:


> Water flow is my present brain teaser.  As this is low tech I don't need CO2 tank levels of flow but I know I still need movement to keep detritus moving to the filters and to transport ferts around the tank etc.  I'm not planning to use the Eheims for flow, other than what a simple shepherds crook or similar can produce.  This will give me longer filter cleaning intervals as flow won't be reliant on filter output which obviously drops with buildup.
> 
> My options as I see them are: pump attached to full length spraybar, or, powerheads (koralia etc)
> 
> What would you guys do?



Please no filtration discussion


----------



## Tim Harrison (10 Jul 2014)

The idea of a full length spray bar seems like an elegant solution - cost effective and good flow and distribution. Although, I suppose it depends on your final layout.


----------



## James O (14 Jul 2014)

I'm hoping for some form of floating plant like amazon frogbit or the mini pistia (water lettuce).  These don't like to much surface movement if memory serves.

Would fish benefit from a variety of flow strengths?  Some fairly fast areas and some quiet little corners maybe?  Can you do this with a spraybar?  Maybe the decor will break it up somewhat?


----------



## Alastair (15 Jul 2014)

James O said:


> I'm hoping for some form of floating plant like amazon frogbit or the mini pistia (water lettuce).  These don't like to much surface movement if memory serves.
> 
> Would fish benefit from a variety of flow strengths?  Some fairly fast areas and some quiet little corners maybe?  Can you do this with a spraybar?  Maybe the decor will break it up somewhat?



Given what you've stated in your initial post,  filter outlets (one either end) I'd just add 2 newave 1600s, one under r each outlet and it'll give you more than ample flow all over the tank. When I wasn't running co2 on my 1400 litre I just ran 2 filters and two newave 1600s and this was more than adequate believe it or not. So I think roughly 6600 litres per hour or a bit less so around 4 times turnover. 
Obviously now with co2 I'm running 2 BIG filters, 2 x Fluval sea 2800 lph pumps, one newave 1600, and a tmc 2200lph pump running the co2 reactor separately so around 9 times I'd say. 

Sent from my D6503 using Tapatalk 2


----------



## BigTom (15 Jul 2014)

Yeah the Bucket was only at about 3x turnover but that was with a full length spraybar. I'd not worry about extreme levels of flow in low tech, just try and find a way of spreading it around the tank efficiently.


----------



## dw1305 (15 Jul 2014)

Hi all, 





BigTom said:


> Yeah the Bucket was only at about 3x turnover but that was with a full length spraybar. I'd not worry about extreme levels of flow in low tech, just try and find a way of spreading it around the tank efficiently.


I don't worry too much about flow either.

It is the much the same strategy that I use for lighting. I use whatever I have to hand, and then adjust the plants mass until it feels about right. I've got Eheim venturi in some tanks, and spray bars in others. I probably slightly prefer the venturi, but I'm not sure it really makes any difference.

I try and ensure that all of the filter media remains aerobic, so I don't really want any organic matter in the filter. I have a fairly large PPI10 sponge pre-filter on the intake, which I clean regularly.

I always have jungles with floating plants.




If I have fish with a high oxygen demand in a larger tank (bigger than ~60 litres) I try to have 2 filters on the tank (usually a pre-owned Eheim external together with an Eheim Aquaball or Maxijet power-head/sponge combination). You can see the Aquaball (and flow from the spray bar) in the picture.

There are more pictures in this thread:
<http://www.ukaps.org/forum/threads/water-lettuce-and-its-impact-on-my-tank.24109/#post-247162>.

cheers Darrel


----------



## James O (15 Jul 2014)

Thanks for the responses guys. 

 I think wavemakers will give me the flexibility I need.  Do you think medium and low flow areas are possible to allow different planting and in tank climates for fish?

I picked up the filters today (thanks Kev) so all I need now is the tank.....


----------



## dw1305 (15 Jul 2014)

Hi all, 


James O said:


> Do you think medium and low flow areas are possible to allow different planting and in tank climates for fish?


 Yes definitely, you can play around with planting and hardscape. Even in tanks that have fish with a high oxygen demand that like flow (_Aspidoras, Hypancistrus etc_), you can create areas where there is low flow. Even fish that like a current will spend times in areas with lower flow.

cheers Darrel


----------



## James O (16 Jul 2014)

Alastair said:


> Given what you've stated in your initial post,  filter outlets (one either end)......



Sorry Just noticed this.  The 2 inlets will be one end and the outlet pair at the other.

I figure one powerhead by the outlets, on the tank end facing along the length. Then another, halfway along the back facing diagonally toward the other tank end and the inlets.  This should make for a more focused flow at the outlet end fading to a more gentle flow at the inlets.


----------

