# How much flow do you actually need?



## gaga43 (Oct 14, 2010)

one of my circ pumps I went to move on its knuckle cause it was blowing too close to my plants and I broke it right off so to eBay I went to buy another and came across these puppies 

It was about 40$ for 4 of them.... I put one on each end of the tank, I also have a smaller expensive little guy was like 60$ for half the size I'd say about 400g/h then for filtration I have ehiem 2217 aprox 250g/h and fluval g6 aprox 150g/h..... So doing the math my tank is having its entire volume turned over 18.5 times in an hour.... 130g tank.... Opinions too much??? I wouldn't say it's not enough


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## loach guy (Jun 2, 2014)

I think that would give you more than enough flow. I just don't think that is enough filtration. I have two 2217's on my 75 gallon, and know of others that do as well. I think that if you added another 2217 you could cut out a wave maker or two.


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## gaga43 (Oct 14, 2010)

As soon as I turned them on junk blew everywhere but has cleaned up now... I may think about getting rid of the g6 and maybe get an fx5 or 6


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## MaroMan (Jan 6, 2010)

I have had a FX5 on my 75 gallon for years and I love it. So much flow in my tank, sometimes I have hard time keeping my stem plants in the substrate! and I have it plummed to go through a uv sterilizer, inline heater and CO2 reactor and still great flow! I say go for it! There is no such thing as over filtration. Good luck!


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## loach guy (Jun 2, 2014)

gaga43 said:


> As soon as I turned them on junk blew everywhere but has cleaned up now... I may think about getting rid of the g6 and maybe get an fx5 or 6


If it was me, I would just add another 2217. Common filters means common spare parts (like the ceramic stem/axle that break easily when dropped or installed improperly) to keep on hand.

Wavemakers are great for getting all of the...stuff...out of the tank. I am not sure as to why they are not more popular in planted tanks considering we can't really vacuum the substrate.


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## burr740 (Feb 19, 2014)

Optimum flow is not just about quantity, efficiency is more important. Gotta be careful using multiple pumps so they dont work against each other, ie flow colliding in the center.

They should work together moving water in the same general direction, ideally, eventually ending up at a filter intake. Or in two non opposing directions if there are two separate intakes, one on each end for example.


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## gaga43 (Oct 14, 2010)

The way I have them positioned made the tank stir all debris they overnight all cleared up


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## burr740 (Feb 19, 2014)

Did it move the debris so the filter could pick it up, or just blow it around to settle somewhere else? Either way it would've cleared overnight.

Im not saying it's a bad thing, just food for thought how it can be tricky incorporating 2-3 pumps in a tank. It's about more than total gph.


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## OVT (Nov 29, 2011)

Your question is a tricky one because the answer depends on a specific tank. Another way to ask the question would be "how little flow can I get away with in this tank?". In some instances, the answer is none. To me, finding the golden middle between the two extremes is more satisfying then finding how many filters, power heads, wave makers, and such I can stick into a tank.

To piggy-back on *burr740*'s good comments, raw gph does not tell you much about circulation or flow or gas exchange. Another consideration to keep in mind is that gph and circulation and flow fluctuate over time.

Yet another consideration is what do you want to get out of "flow"? Filters provide multiple functions: water circulation, mechanical, biological and chemical filtration. How much of which do you want or need? Throw in in-line CO2, heaters, UV for more fun.

Anyways, a good topic. imho.


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## Nordic (Nov 11, 2003)

Ideal placement is a little counter intuitive I think.
If you want to circulate cold water from the tap on one end to the other side of a bath, you don't fan the centre of the water with your hand. No, you set up a stirring motion close to one of the sides, pushing water to the back down one side, and water from the back returning down the other side. To do this in a tank, you would place one pump on the centre of one long side pushing one way, and another on the opposite side pushing the other way.
Bet it would stir the water around much more than one would anticipate as the moving water has a bit of a flywheel action going.


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## roadmaster (Nov 5, 2009)

I much prefer mounting my two spray bar's high on the back glass pointing toward's the front glass.
Both intakes mounted one on each end of the tank ,also on back glass.
Creates flow like a barrel rolling towards you.
Water hit's the front glass,travel's down the glass to the substrate,across the substrate from front to back,back up the back glass,and repeated all day.
Detritus,mulm.etc collect's near the intakes in each corner and is drawn back into the filter.
Work's quite well.


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## houseofcards (Mar 21, 2009)

I think flow in planted tanks is very overrated. In FO tanks yes, the filter size and media is very important, but in planted I don't think you need more than just good adequate flow. With plants debris is getting stopped by the plants and ends up in the substrate regardless. 

Most eheim filters (marketed for planted tanks) are judged on their efficiency and are easily outgunned by the competition on flow rate. I'm not saying high flow rates are necessarily bad (depending on setup) just not necessary. 

I never understood the power head thing in a 2-4 foot tank, unless your running a small HOB. The spraybar from a canister filter should be more than enough to carry ferts, etc to anywhere.


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## sevendust111 (Jul 15, 2014)

For me, flow made a huge difference. I have a 20L with 2 Aquaclear 30s. I inject with an atomic diffusor. The co2 was mostly circulating in a cyclone around half the tank because of the filter close by. When I put a nano powerhead right above the diffuser, I immediately saw a difference. Pearling was more evenly dispersed and my drop check on the other end of the tank finally turned green.


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## houseofcards (Mar 21, 2009)

With an HOB as I mentioned in my previous post I could see the powerhead more, since the flow isn't always horizontal across the tank based on the condition of the filter and the water level. It also depends where the diffuser is placed in the setup.


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## roadmaster (Nov 5, 2009)

True enough ,plant mass,hardscape, can block flow to some area's .Can also block ability of plant's to get nutrient's and CO2 carried by said flow to these area's.
Add to this dirt that accumulates in filter over time,other apparatus plumbed into filter,and flow is further decreased.
Is why flow is considered of great importance to some ,for increased flow can help compensate for the afore mentioned.
I have found it to be of value in my effort's with the aquatic weed's .


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## gaga43 (Oct 14, 2010)

The power heads are making the filtration more effective, when everything is blowing around it passes by the intake more and gives it more of a chance to be sucked up... I have both returns in the middle and the intakes at each end


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