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Discussion: Are we obsessed with circulation and flow?

Peter, we had our first big discussion way back a couple years ago when Matt started the thread High Water Turnover - discuss This wasn't necessarily my idea though. Barr was an advocate of high flow way before that. I just plagiarized his ideas.

I'm always suspicious of claims that contradict the fundamental principles though, so even though George states that folks abroad report great success with varying combinations of high light, low flow and lean dosing if we were to do a more thorough investigation (you know, like those guys in Crime Scene Investigation) I'm betting that we'd find either inconsistencies, mitigating circumstances or tradeoffs.

For example, using a low light, lean dosing approach is not an impossible task, but we should find that the hobbyist would require a lot longer to achieve the level of plant mass that is displayed in the final product.

Another claim is that lean dosing and high light works a charm, but if we were to look deeper at the tap water properties, we might find that the hobbyist is unaware that his water is very high in NO3/PO4 which may or may not be revealed by hobby grade test kits.

Low flow could work, but what kind of scape is it? An open Savannah is much more forgiving of low flow, low CO2.

As bright and impressive as metal halide lamps look up close, the energy falloff is significant so that a 6 inch or 1 foot difference in placement height lowers PAR due to the inverse square property of light. I recall Barr taking measurements of some official Amano tanks where the data revealed the tanks were actually low light.

Because we are normally seeing the finished product, we not be aware of all the trials and tribulations that the hobbyist went through with that particular tank. Does Amano get algae? You bet! Does he have to clean it? No, he has an army of devotees that do the elbow work for him. I'd be very careful about drawing conclusions just because we are told something or just based on the finished product.

We already have plenty of empirical evidence which shows us how effective high flow, good distribution techniques and adequate dosing are at solving problems. We see the results of excessive lighting. Physics and biochemistry cannot work differently in UK than it does elsewhere. We know, in our tanks that when we tick all the major boxes, the tank becomes algae free.

Experienced and clever hobbyists can make a purse out of a sows ear, so that particular tank, although seemingly paradoxical is a result of that hobbyists understanding of how to get around the particular limitations.

We also know that all the boxes must be ticked. High flow alone, without regard to the other requirements won't solve all problems. On the other hand, if high flow were the only box not ticked this might not cause that many problems. We have to approach tank husbandry holistically, not from an isolated or tunnel vision perspective. Some people can't afford a bigger filter or perhaps it won't fit in the cupboard. Well, that means they'll have to pay special attention to light, injection and distribution techniques.

We don't know how much elbow grease, terry cloth towels and newspapers were used on a tank to clean the surface of scum and to clean the glass or rocks just before that spectacular award winning piccie was snapped. :shh:

Cheers,
 
George Farmer said:
zig said:
I do remember George and Dan talking about 10X flow rates thats where I picked up on that idea first of all.
I first discussed it in a 2006 PFK article, I think. I wondered if anyone else would remember!

Yes, credit where credit is due. I heard it here (UKAPS) first of all, I didnt read it in PFK although you probably did mention it there in print earlier then I would have heard it here. I remember it well, it was you who mentioned it in a thread here probably early 2007 regarding a conversation you had with Dan, I remember it making 'sense' at the time and took note, the rest is planted tank history as they say, sales of large external filters have rocketed ever since :D
 
zig said:
...sales of large external filters have rocketed ever since :D
lol! Probably quite true!

I remember first reading about it from one of Justin Law's early 'scapes and he used an Eheim 2224 on a 35 litre.

When I first wrote those articles there was so much stuff that blew away a lot of the old school theories (a lot of credit to Mr Tom Barr too, of course) - the editorial team loved it! Good ol' days!
 
They did, I remember Jeremy remarking that tetra wouldn't be bringing the ex400 into the country because we were "turnover hungry" and as result there's no market.
 
ceg4048 said:
Peter, we had our first big discussion way back a couple years ago when Matt started the thread High Water Turnover - discuss This wasn't necessarily my idea though. Barr was an advocate of high flow way before that. I just plagiarized his ideas.

I'm always suspicious of claims that contradict the fundamental principles though, so even though George states that folks abroad report great success with varying combinations of high light, low flow and lean dosing if we were to do a more thorough investigation (you know, like those guys in Crime Scene Investigation) I'm betting that we'd find either inconsistencies, mitigating circumstances or tradeoffs.

For example, using a low light, lean dosing approach is not an impossible task, but we should find that the hobbyist would require a lot longer to achieve the level of plant mass that is displayed in the final product.

Another claim is that lean dosing and high light works a charm, but if we were to look deeper at the tap water properties, we might find that the hobbyist is unaware that his water is very high in NO3/PO4 which may or may not be revealed by hobby grade test kits.

Low flow could work, but what kind of scape is it? An open Savannah is much more forgiving of low flow, low CO2.

As bright and impressive as metal halide lamps look up close, the energy falloff is significant so that a 6 inch or 1 foot difference in placement height lowers PAR due to the inverse square property of light. I recall Barr taking measurements of some official Amano tanks where the data revealed the tanks were actually low light.

Because we are normally seeing the finished product, we not be aware of all the trials and tribulations that the hobbyist went through with that particular tank. Does Amano get algae? You bet! Does he have to clean it? No, he has an army of devotees that do the elbow work for him. I'd be very careful about drawing conclusions just because we are told something or just based on the finished product.

We already have plenty of empirical evidence which shows us how effective high flow, good distribution techniques and adequate dosing are at solving problems. We see the results of excessive lighting. Physics and biochemistry cannot work differently in UK than it does elsewhere. We know, in our tanks that when we tick all the major boxes, the tank becomes algae free.

Experienced and clever hobbyists can make a purse out of a sows ear, so that particular tank, although seemingly paradoxical is a result of that hobbyists understanding of how to get around the particular limitations.

We also know that all the boxes must be ticked. High flow alone, without regard to the other requirements won't solve all problems. On the other hand, if high flow were the only box not ticked this might not cause that many problems. We have to approach tank husbandry holistically, not from an isolated or tunnel vision perspective. Some people can't afford a bigger filter or perhaps it won't fit in the cupboard. Well, that means they'll have to pay special attention to light, injection and distribution techniques.

We don't know how much elbow grease, terry cloth towels and newspapers were used on a tank to clean the surface of scum and to clean the glass or rocks just before that spectacular award winning piccie was snapped. :shh:

Cheers,

I was cross posting there earlier ceg, giving George all the credit, so missed your post. Probably going to be cross posting here as well, I will catch up!! Still reckon it was George and possibly Dan who came up with the 10X flow guideline that we use now for highlight tanks. I would have been a pretty active reader back in those days of all the forums and while more flow may have been discussed nobody had really pinned it down as such and suggested guidelines for filter flow rates or tank turnover so that was a move forward at the time that no one had suggested before , it was a good starting point for where we are now.

I agree with your views though, lots of smoke and mirrors in this hobby, and as you say the laws of physics and biochemistry are the same this side of the world as they are on the other side, we cant get away from that no matter what we argue.

It goes back to that old cliche of planted tanks IMO. Its the balance between CO2 levels ,circulation and lighting levels in highlight tanks (and ferts obviously but thats probably the easiest thing to control you just dump that in 3x per week with EI method) cliche's but so true IME.

My own experience tell me that without having first of all good CO2 levels you are going to struggle anyway, thats really the key for me anyway the rest you can control easy enough. You can have lots of flow but if you have low CO2 levels you will definitely get algae soon after. On the other hand if you have good diffusion methods for CO2 levels but are not circulating it properly you will also get algae eventually. So you need a balance between the two.

Light levels come into the mix as well, use too much and you are also going to struggle even with good circulation/CO2 methods, CO2 needs to be spot on in that case so you are better off not chasing that particular dragon.
 
I wonder how important a rich substrate is? If you have a substrate releasing loads of CO2 and nutrients from the base then circulation and lean dosing may not be that important because the plant food is already right where the plants need it. But if you use an inert substrate then maybe flow is vital to get the added ferts and injected CO2 evenly distributed.

I have often wondered about the importance of flow because on the rare times I maintain my filter I find it is often blocked so much that it has hardly any flow yet the plants and fish seem fine (although it is a low light low tech tank).
 
I was about to do a mega post until I read Ceg's and he has basically said what I was going to say. Brenmuk above has also added the little that was left.

basically we talk flow but mean circulation. If we say 10x flow then we are meaning after flow reduction in the filter (actual output) 5-7x. Thats not to say that we need 5-7x but that it should guarantee much better circulation. If you fill your car up you put more petrol than you need into the tank and then know it will get you to where you want to be :)

As per Brenmuks post I think some substrates (especially older ones) will also be spreading nutrient at the base of the tank and providing CO2.

On the light issue I am not so sure that many of those supposed highlight tanks were actually highlight. As Ceg says the ADA MH which on spec are highlight actually turned out to be pretty lowlight when PAR tested. Many of us may think we have highlight when actually we have lowlight. Maybe the opposite can be true too causing the user to wonder why their 'lowlight' tank is having so many problems.

The plantmass is pretty important to all aspects. Lots of plantmass can turn highlight into lowlight due to shading or coverage etc.

On the 'unseen' part I am pretty sure that many of those tanks look a little different an hour or 2 prior to show/photoshoot. Glass cleaning, pruning off the odd leaf, scrubbing rocks, cleaning substrate etc. Who knows the extent of cleaning undertaken but in some cases at least I would suspect quite a lot.

I personally leave mine as is which Saintly can testify to. When he photographed mine he asked me to remove 1 dead leaf. He can tell you how clean the rest was though. lol.

I don't put it down to the filter flow at all though. I have just under 6x (before flow reduction) and my filter is absolutely clogged at the end of each month so will be nearer 1 or 2x. Circulation is key though and the 12x turnover provided by a Koralia is what solved CO2 problems and at the same removed every algae from the tank I was having problems with :) Is circulation important? I had some algae issues due to CO2/nutrient delivery before the Koralia and they disappeared completely after.

So on paper I currently have 17.6x turnover although the 5.6 provided by the filter will be a lot less most of the time :)

AC
 
Hi all, Brenmuk wrote
I have often wondered about the importance of flow because on the rare times I maintain my filter I find it is often blocked so much that it has hardly any flow yet the plants and fish seem fine (although it is a low light low tech tank).

I've run a lot of low tech. non CO2 tanks with lots of biological filtration and gas exchange capacity, but virtually no flow (You can do this using wet/dry trickle filters like the "de Bruyn" filter and an in tank "Hamburg Matten Filter" type filter (can be a large foam block rather than a real HMF)). I've never done this on a tank deeper than 15", but this approach works well on shallow "jungle" tanks, and is my preferred approach for Killi's etc.

More than once I've turned the filter of and then failed to turn it back on, in some cases for at least a week and possibly up to a month without ill effect.

cheers Darrel
 
dw1305 said:
More than once I've turned the filter of and then failed to turn it back on, in some cases for at least a week and possibly up to a month without ill effect.
cheers Darrel

Who put this clown`s name forward for expert status? :lol:

Personally, I am very skeptical of peoples` claims for the parameters, algae levels etc, and Amano in particular. My 240l was a complex scape that wouldn`t have happened without x2 1200l filter turn over and x 2 Koralia power heads. TA has an army of assistants closely watching his tanks and stomping on any algae issues at the first opportunity.

I don`t obsess with flow, as I hate hardware in my tanks, but sometimes glass lily pipes just won`t cut the mustard, particularly with hard scape and plants reaching up in to the water column.

Dave.
 
I did have what I wanted to say clear in my own head but now ive forgotten the point...
Anyway, I think what I wanted to say was somewhere along the lines of..
Regardless, of what other people state are basic requirements, 10x flow certain concentrations of ferts light intensity etc, in my personal experience everyone else's experience counts for nothing! To me anyway. After months of failure, algae poor growth, livestock dying, surface scum, etc. Sticking to the rules and following others advice, gleaming information from the net on other peoples setups left me in a right mess. Most of it is rubbish, Not always for them but deffinitely for me.
Only through repeated failure and systematic changes, keeping a record of those changes did I ever see any improvement, and i'm not even there yet.
For me 10x flow would be bad advice, probably works well for others though. I need to run min 20x (10x in real terms) or stuff starts dying. My lighting wouldnt even be considered high compared to figures you can get from other sites and other peoples setups.
There is a lot of misleading info out there (oppinions stated as facts), some of its true for them some of its outright lies. Its all irrelevant to me now.
I try something, if it works I might adopt it, if it fails I discard it. This does'nt mean it wont work for you.

Oops ive been goin on again! Its election fever got me all ranty! :rolleyes:
 
Hi all,
Who put this clown`s name forward for expert status?
Dave I know exactly what you mean and think you may have made a valid point, but I probably should have said that it is just carelessness rather than a planned experiment, and I definitely don't recommend it.

I think Diana Walstad originally thought that a filter and water circulation wasn't essential for the low tech. planted aquarium, but after further experimentation changed her mind and recommended both some form of biological filtration and method of water circulation.

cheers Darrel
 
True, I've got two pdfs of hers and one states no filter or water movement is needed, in the pdf of ecology of... she states both are vital.
 
I had a fairly low instance of algae in my tank in the beginning months (had some brown dust algae and BBA)up until about 2 months ago when I reduced my 400 ltr tanks flow down to 800 ltrs/hr (as rated on pump) during the night so my newly planted HC wouldnt uproot. It all went to hell from there on in... I have been battling BGA, BBA, Brown dust and that nasty green stuff thats hard to scrape off the glass) ever since. The substrate would turn black every few weeks. I have since removed some plants which were obstructing the water flow from my outlet and added another 1500/ltr/hr (as rated) pump. Which leaves me at 2400/ltrs/hr of filtration and 3900/ltrs/hr (rated) of flow.

All of my shrimp died aswell and the new ones I bought are too small to put into the tank yet so I have been scavenging native aquatic snails from my local river. So bare in mind that I have had no help from aquatic algae eaters.
 
Hi all,
Sorry to hear that Fishbeast, I think the problem is probably to do with the balance between CO2, nutrients and light, the lower flow lead to fluctuating levels of the CO2 and nutrients, and then your problems started. In my case I had relatively low flow, CO2 and nutrients and a lot of biofilm (additional biological filtration capacity) to start with, so it isn't so much of a change when the filter was off.

This is one reason I like low-tech., changes tend to be slow and this gives you more time, and more of a chance to rectify things before they get out of hand.

cheers Darrel
 
Algae isn't about too much light vs nutrients, CO2, flow etc, is it not about the ammonia levels?

Did Tom Barr not say that ammonia is the algae trigger, so healthy plants = little to no ammonia as the plants are taking it up before any algae can take advantage...

Is the wpg rule not also tank size dependent? As in smaller tanks need a higher wpg ratio compared to larger ones?

Or I may be missing something.
 
Hi all,
Or I may be missing something.
Have a look a this thread:

http://ukaps.org/forum/viewtopic.php?f=11&t=3217

It has quite a lot of detail and some intersting points from Clive, Dusko and JamesC etc. Personally I always have some algae (but rarely a lot) and usually the full of range of possibilities in my tanks. Another fact to remember as well is that "algae" is a cover all term to talk about very different organisms, "Green algae" had some similarities to higher plants (same chlorophylls etc.) but a red algae like BBA is as different from a green algae or a diatom as you or I are, and BGA are even more different again.

cheers Darrel
 
nry said:
Algae isn't about too much light vs nutrients, CO2, flow etc, is it not about the ammonia levels?

Did Tom Barr not say that ammonia is the algae trigger, so healthy plants = little to no ammonia as the plants are taking it up before any algae can take advantage...

Is the wpg rule not also tank size dependent? As in smaller tanks need a higher wpg ratio compared to larger ones?

Or I may be missing something.
Algae is ALWAYS about too much light. This is one of the reasons blackouts work to eradicate or at least to mitigate the bloom. The combination of light and ammonia is simply a double whammy. Higher ammonia production rates require less light to trigger a bloom, that's all. Higher wpg in smaller tanks is specifically the reason there are so many small tanks with algae.

Cheers,
 
I have a very healthy looking nano which i have been putting down to reasonable.
Its about 1.5wpg, and the moss that is sat right next to the outlet needs trimming very regularly, whereas the moss further away is less often so.
I think its certainly one sort of plant that definitely benefits from the higher flow.
 
George Farmer said:
It's interesting the rise in popularity of Korilias. Eye-sores IMO, especially when contrasted against glassware. Function over form is necessary sometimes though.

I do not like them, I do not use them.

I use Vortechs or small discrete pumps and try and hide them best I can.

I think with low light, patience, low nutrients(who knows what's in the sediments though.........) CO2 is much less critical, so is the flow.

But, with few fish, this ain't gonna matter much. With more fish, more light, more plant biomass, then you have issues.
The mechanisms are all the same in such tanks, just the rates are different, so it appears to contradict the general dogma.

But we know non CO2 planted tanks still grow plants, correct?
What's the difference between that and CO2?
The rates of growth.

What else can change that?
Light, which is not expressed in any comparable metric (eg PAR). ADA's tanks are all low light, nutrients are very rich in the sediment, low stocking levels(10-30% of what I add). So there's some missing information, that when accounted for and measured, suddenly make a lot of this make a lot more sense.

It's not a fair comparison unless you use the right metrics and measure the right locations/methods.

Ole and Troels pointed this out very well with this article regarding CO2 and light:

http://www.tropica.com/article.asp?type ... tic&id=142

Similar replacement matrices can be done for circulation and sediment/water column nutrients also like the above.
But similar results will ensue.

As resources and rates of diffusion are reduced, so shall growth rates of the plants, this does imply the plants will look bad, just slower growth.

Which often is more manageable.
So kudos to lower light. :thumbup:



Regards,
Tom Barr
 
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