# DIY filter flowrate too slow?



## HappyGrimgore (Dec 4, 2015)

So I've just done up a DIY canister filter of sorts. It's a 3" pipe filled with lava rock. my pump is quite powerful, though the output after my filter seems to be very slow... is there a better media that would let more water through at a faster rate? I'm just worried that my pump is working too hard and will burn out.


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## somebody (May 13, 2014)

Shake it make sure there is no air in the pump.

What's the feed / return line size (i.d)?
How high is the highest point from the lowest point in the filter?
What pump?


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## somebody (May 13, 2014)

I just checked out your other thread. It looks like you have 5 outputs on 1/2 inch pex pipe am I right?

If so go around your house and turn on all the faucets you can..... same concept. Your pressure might be high enough but there's no back pressure to shoot it like a sprinkler. Your return might be 1000 gph but coming from 5 outputs that's 200 per output roughly. Other factors are output diameter, distance down the line for the output, the amount of turns in your outputs. Water is going to follow the least path of resistance.


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## HappyGrimgore (Dec 4, 2015)

there are 5 outlets, If I cover 4 of them, its still lower than it should be... I know the micron filter size will cut down on some flow as well, 5 micron is very small. I can bypass the filter to get the flow up a little, but still quite low. I'm thinking its the overall distance and height, combined with the packed in lava rock. just so much resistance there.

Its a 3/4" output from the pump, to my 3" filter, then down to 1/2" return to tank. the tank height is 24", so its a lot for the pump to push. I could, in theory move the pump outside of the tank and build it in-line, but I'm not sure that's the way I want to go.


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## somebody (May 13, 2014)

Yea that's a lot of places for pressure drop to occur. Few suggestions/ reccomendations..
1) go up from 5 micron. 5 micron is extremely small especially for primary filtration (or run more 5 micron filters in parallel) if I'm not mistaken it's 200 gph (atleast the ones I've looked at before) max output. 
2)increase return line size from 1/2 to 3/4
3)remove one output and only have 4 going the same way.


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## wryan (Dec 6, 2015)

Anyway you can get gravity and pressure working for you, instead of against you ?

IOW, would it be possible to do any of the following:

1. Mount filter(s) above the pump.

2. Keep the output/upline from the pump at a smaller diameter, to minimize head pressure that pump has to fight against.

3. Install filter(s) into a downline, below the highest point of your plumbing.

4. After the plumbing hits it's highest point, upsize the pipe used for the downflow.

IOW, lets say you are using 1/2" or 3/4" line coming out of the pump. This travels up a couple of feet (or whatever), to it's peak point. After that peak point you upsize a section of the downflow pipe to 1" (or 1 1/2" or 2") ... the weight of the water in the larger section of pipe will act to develop pressure. Then, after some distance, you would reduce the pipe to fit your filter(s), which would increase the pressure even further. Install a ball valve before your outlets, to prevent the downpipe from completely emptying itself due to unrestricted flow.

This is basically how water towers in municipal water systems work.


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## somebody (May 13, 2014)

Treatment facilities do this because it works yes but it will not work on a tank because the output of the water supply is at the same level. Instead of thinking as the water tower is a pump think of it as your aquarium and the pipes to the homes are your gravel vac. The water tank is higher and gravity feeds into supply lines underground which then supply homes.

I theory your plan of reducing piping and hosing diameter should work but instead it's exact opposite because you are dealing only with pressure and not a *vacuum*.

When supplying the filters in this case you have two choices put the pump as pumping in or pulling out (reccomended*). Either way you cut it 50 lbs of vac or 50 lbs of pressure is the same it's the volume here we are worried about which is why it seems to be "low flow". You have your pump before the media it encounters resistance on everything it touches (string filter, bio balls, whatever media inside the pvc). Unfortunately you will encounter the same issue with it set up to pull. So why is pulling better because I'd rather deal with air in the line than 120 gallons of tank water on the floor from a leaky pvc connection.

You need to increase volume allowed to go through the system and not really fight a pressure. If you increase the volume it spreads the rate of friction over a larger area thus increasing your rate and making your return seem like more.

Try without the 5 micron filter first I really think you will see a major difference with that alone.

You don't put your water change bucket on top of your tank you put your bucket on the ground to create a siphon. When you use water at the house it draws a vacuum at the tower strong enough to pull the equal amount of water removed from the tower,up, because of increasing pipe diameter and a stronger vacuum.

Yes you are right wryan but it won't work when the houses are just as high as the tower.


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## wryan (Dec 6, 2015)

somebody said:


> Treatment facilities do this because it works yes *but it will not work on a tank* ...


... really ?

Why ?



somebody said:


> ... because the output of the water supply is at the same level.


Actually, the output of the water supply (back into the aquarium) is slightly higher (than the pump level)



somebody said:


> Instead of thinking as the water tower is a pump think of it as your aquarium and the pipes to the homes are your gravel vac.


I'm not thinking of the water tower as a pump - I'm thinking of it as a complete, integrated system ... one which includes a pump to fill the tank (the larger diameter pipe) and uses gravity to increase pressure (and thereby flow) out the drain.



somebody said:


> The water tank is higher and gravity feeds into supply lines underground which then supply homes.


Yes, that is correct.



somebody said:


> I theory your plan of reducing piping and hosing diameter should work but instead it's exact opposite because you are dealing only with pressure and not a *vacuum*.


Huh ?

Fact is, under the system I have described one is dealing with both pressure and a vacuum (by virtue of weight and gravity) - at different points in the system.

And I'm not suggesting the OP reduce the output line from his pump to anything smaller than what is recommended by the mfg.



somebody said:


> When supplying the filters in this case you have two choices put the pump as pumping in or pulling out (reccomended*). Either way you cut it 50 lbs of vac or 50 lbs of pressure is the same *it's the volume here we are worried about* which is why it seems to be "low flow".


That's true ... however I did not suggest that my suggestions alone should be used to the exclusion of anyone else's.



somebody said:


> You have your pump before the media it encounters resistance on everything it touches (string filter, bio balls, whatever media inside the pvc). Unfortunately you will encounter the same issue with it set up to pull.


Assuming no other changes, then perhaps so ...

One thing the OP would not be encountering however is additional head pressure, due to the weight of the water in a larger diameter pipe on the pump output side.



somebody said:


> So why is pulling better because I'd rather deal with air in the line than 120 gallons of tank water on the floor from a leaky pvc connection.


If the PVC pipe leaks it's gonna be a mess anyway you cut it.



somebody said:


> You need to increase volume allowed to go through the system and not really fight a pressure. If you increase the volume it spreads the rate of friction over a larger area thus increasing your rate and making your return seem like more.


No argument there.



somebody said:


> Try without the 5 micron filter first I really think you will see a major difference with that alone.


Very likely.



somebody said:


> You don't put your water change bucket on top of your tank you put your bucket on the ground to create a siphon. When you use water at the house it draws a vacuum at the tower strong enough to pull the equal amount of water removed from the tower,up, because of increasing pipe diameter and a stronger vacuum.
> Actually, they use pumps to fill the towers ... and a gravity is what drains them :wink:
> 
> 
> ...


[/quote]
In this case the "house" (aka "aquarium") wouldn't be as high as the tower - it's lower.


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## HappyGrimgore (Dec 4, 2015)

I calculated my pump output, its about 1gallon per minute. - so its only turning my tank over once every 1.5 hrs. no good!

I put a bypass on the big filter - If I bypass the 5 micron filter, and bypass the lavarock filter at the same time, there is very little difference in pressure or volume. I think this is going to come down to my pump not being strong enough. With everything on bypass, that water should be a flyin' out - which it is not.

I also cut off my manifold, so there is one stream of water, not split up into 5. still no major difference.

any recommendations on a nice big pump? preferably that doesn't cost me an arm and a leg?


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## HappyGrimgore (Dec 4, 2015)

http://www.inyopools.com/Products/07501352024304.htm

This is the pump I currently have in the tank - Its not an aquarium pump, I know!


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## wryan (Dec 6, 2015)

HappyGrimgore said:


> I calculated my pump output, its about 1gallon per minute. - so its only turning my tank over once every 1.5 hrs. *no good!*


Yup.



HappyGrimgore said:


> I put a bypass on the big filter - If I bypass the 5 micron filter, and bypass the lavarock filter at the same time, there is very little difference in pressure or volume.


That points - at least to some extent - to there being "issues" (unnecessary head, too many 90's, etc.) with (the design of) your plumbing.



HappyGrimgore said:


> I think this is going to come down to my pump not being strong enough. With everything on bypass, that water should be a flyin' out - which it is not.


See my next post re: derating of pumps.



HappyGrimgore said:


> I also cut off my manifold, so there is one stream of water, not split up into 5. still no major difference.


See my second comment in this reply above.



HappyGrimgore said:


> any recommendations on a nice big pump? preferably that doesn't cost me an arm and a leg?


Define "an arm and a leg" ...


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## wryan (Dec 6, 2015)

The rating for that pump (350 gph) is probably figured at zero (0) feet of head - meaning that the pump isn't having to push the water up against the pressure created by the weight of the water it's already pushed through above it ("aka back pressure")

The pump will *de-rate* (aka lowered output) according to how much/how many (feet of) "head" it's pushing against. Although Danner does not publish the specs for that particular pump at various* head heights*, they may do so for others - which might give you some insight as how much having any head at all, will effect things.

Adding a couple of feet of head may cause the output to fall off significantly - perhaps by as much as half (dependent on the design of the pump and plumbing, etc.)

And if it's pushing against a large(er) pipe (water column) on the vertical rise, the back pressure will be increased by virtue of the fact that "weight + gravity = pressure"

However, by incorporating a larger pipe on the downward portion - particularly near the top of the downward portion of the piping run - I believe the head pressure would be substantially reduced, if not entirely eliminated (assuming an open run of pipe with no obstructions whatsoever) ... basically the vacuum of a siphon.

The larger the diameter of the pipe and the longer the run, on the downward side, the greater the pressure developed.


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## wryan (Dec 6, 2015)

For clarity's sake:



wryan said:


> The larger the diameter of the pipe and the longer the run, on the downward side, the greater the pressure developed.


Should read:

_"The larger the diameter of the pipe and the longer the run, *on the downward side*, the greater the pressure *and flow* developed, *all else being equal* ..."_


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## somebody (May 13, 2014)

Maybe we should have started with the 350 gph rating :lol: would have saved a lot of arguing back and forth.


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## wryan (Dec 6, 2015)

FWIW, here's the output specs for a Danner "Supreme" brand Model 3 Mag Drive pump at various head heights.

Nominal: 350 GPH
Watts: 37
GPH at 0': 480
GPH at 1': 405
GPH at 3': 335
GPH at 5': 270
GPH at 7': 170
GPH at 10': -
GPH at 15': -
Shutoff: 10.5'

Probably run you around double ($70) of what you are using now ... but it is likely capable of providing more volume (at various head heights) than what you currently have - despite having the same rated flow.


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## wryan (Dec 6, 2015)

somebody said:


> Maybe we should have started with the 350 gph rating :lol: would have saved a lot of arguing back and forth.


 :lol:

:wink:


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## HappyGrimgore (Dec 4, 2015)

I took some time and replumbed it... Here's what I did:

- I eliminated 4 90's 
- raised the initial filter by a couple of inches to be on the same level as the lavarock filter
-took out the bypass

none of it made a difference at all in the pressure/volume - the bypass on the 5micron is a little better than before, but no difference when on "full filter". So I will go ahead and say that I agree with Wryan, it being a head issue ( wouldn't be the first time someone's told me theres something wrong with my head! )


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## wryan (Dec 6, 2015)

_"... ( wouldn't be the first time someone's told me theres something wrong with my head! )"_
LOL ... BTDT.

Much of the issue may stem from the fact that it's probably an inefficient pump design - from the sound of it, it almost sounds like it is designed to pump water off a pool cover.

The need for a more efficient pump that can handle higher head heights probably just isn't needed for it's intended use.

And there's probably a good reason that the pump's actual capacity at various head height isn't published by Danner.


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## somebody (May 13, 2014)

I feel he needs a larger pump period. One rated for constant use. Filtration should turn over 10x/h for heavier stocked tanks. You can never go wrong with to much filtration. Plus if it's too turbulent then you can always install a ball valve or add larger/ more outputs to help regulate the flow and spread 1200 gph over 12 outputs rather than 4 or 5. That's what I like about diy the "costamizeability" if it.


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## HappyGrimgore (Dec 4, 2015)

yup, I totally agree now, after hearing the opinions and looking some stuff up. It's used, like you said, for pumping water off of a pool cover, its known as a 'cover pump' as it says on the sticker. I've ordered a submersible pump from Amazon, 900GPH for around $50 - I'm sure the quality will be a little less than stellar, but its what I can afford, and will put to rest the theory that its a head issue! Will update next week when it comes in!


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## somebody (May 13, 2014)

:thumb: standing by for updates


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## wryan (Dec 6, 2015)

somebody said:


> I feel he needs a larger pump period. One rated for constant use. Filtration should turn over 10x/h for heavier stocked tanks. *You can never go wrong with to much filtration*.


Like you say: It sure couldn't hurt.

:thumb:



somebody said:


> Plus if it's too turbulent then you can always install a ball valve or add larger/ more outputs to help regulate the flow and spread 1200 gph over 12 outputs rather than 4 or 5. *That's what I like about diy the "costamizeability" if it*.


Yup.


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## wryan (Dec 6, 2015)

HappyGrimgore said:


> yup, I totally agree now, after hearing the opinions and looking some stuff up. It's used, like you said, for pumping water off of a pool cover, its known as a 'cover pump' as it says on the sticker. I've ordered a submersible pump from Amazon, 900GPH for around $50 ...


If it works out and you are happy with it, PM me a link to the pump ... if you don't mind.

I just recently pulled out my tanks from storage and started to set things back up. I have a 55g and 10g up and running currently, with two more to go. The 55g is using a partially home-brewed reverse-flow undergravel filter, which is being fed by a Marineland Magnum 330 canister filter (supposedly 330 gph - probably at 0' head) ... which isn't providing as much flow as I would really like.

That's probably due, at least to some degree, to head issues - I had the 330 below the tank on the floor, but have since moved it up to a table, next to the tank (but still slightly lower) - so in addition to whatever head it's fighting to get the water back up to the tank, it also has to push against the weight of water (to the depth/bottom of the tank - about 20") to feed the RFUGF.

I also have a Magnum 200 on that tank, with the Micron Filter cartridge and D.E. ... so the tank is staying pretty clean ... but the filter maintenance on the 200 with the Micron Filter is a little much to commit to long-term (it has to be cleaned about 1x per week)

Ideally, I'd like to feed the RFUGF with a pump/powerhead in the 600 gph or better range.



HappyGrimgore said:


> I'm sure the quality will be a little less than stellar, ...


Ya just never know ... could end up being a lot of bang for the buck.



HappyGrimgore said:


> but its what I can afford, ...


I can certainly appreciate that ... :wink:



HappyGrimgore said:


> and will put to rest the theory that its a head issue! Will update next week when it comes in!


Keep us posted on what you you find out.


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## HappyGrimgore (Dec 4, 2015)

Pump came, and was quickly packed up for return - it did provide a better flow rate after the filters, but not nearly enough. it improved the 1.5hr turnover rate to about 1hr. it was also very loud, and i doubt the fish would like it if they were put in.

Im thinking i may need to just reconfigure how im set up here, maybe putting the pump under the tank in a bucket and using a siphon instead of having the pump in-tank.


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## HappyGrimgore (Dec 4, 2015)

One further update - I decided as one last effort to switch the order of my pump and filters. I moved the pump to the back-end of the filters, so it would use its suction power to pull the water through the filters, instead of push. it seemed to work, and I got my pressure back up - only thing is, while I was doing this, I broke my pump- seemed to split the plastic casing - and so I had to order another one to replace it.


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## somebody (May 13, 2014)

I use a Rio 26hf in my sump and I got to say this pump really takes a lickin and keeps on tickin. I had the 20hf but after a year of constant use I was ready to upgrade my flow rate. Pumps,IMO, are something that you yearly get what you pay for.


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## HappyGrimgore (Dec 4, 2015)

I ended up ordering another Danner pump, but this time its a pond pump, 700gph, that I will run in-line instead of submerged in-tank. I really wanted to eliminate as much of the internal noise as possible, as well as cleaning up the look of the tank. I also took the opportunity to take apart my lavarock filter, rinse the rock off (since its sitting there, with no water going through it anyways), and put it back together in a way that I can easily take it apart if necessary.

I also took out some plastic mesh material I was using to keep the rock from getting pushed out of the filter - I took this out as I thought maybe it was helping to restrict the flow as well... Do I need to worry about my pump sucking up rock??? I have a large piece of lava rock at the pump end that should stop any large chunks from getting sucked in..


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## wryan (Dec 6, 2015)

HappyGrimgore said:


> I ended up ordering another Danner pump, but this time its a pond pump, 700gph, that I will run in-line instead of submerged in-tank. *I really wanted to eliminate as much of the internal noise as possible, as well as cleaning up the look of the tank*.


Makes sense.



HappyGrimgore said:


> I also took the opportunity to take apart my lavarock filter, rinse the rock off (since its sitting there, with no water going through it anyways), and put it back together *in a way that I can easily take it apart if necessary*.


Good idea ... :thumb:



HappyGrimgore said:


> I also took out some plastic mesh material I was using to keep the rock from getting pushed out of the filter - I took this out as I thought maybe it was helping to restrict the flow as well...


Depending on the size of the mesh, it may well have been restricting it.



HappyGrimgore said:


> Do I need to worry about my pump sucking up rock???


Hard to say, without knowing the actual size of pipe/line you are using on the pump intake ... and the size of the rocks.



HappyGrimgore said:


> I have a large piece of lava rock at the pump end that should stop any large chunks from getting sucked in..


Well, there ya go ... :wink:


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## wryan (Dec 6, 2015)

HappyGrimgore said:


> One further update - I decided as one last effort to switch the order of my pump and filters. I moved the pump to the back-end of the filters, *so it would use its suction power to pull the water through the filters, instead of push*. it seemed to work, and I got my pressure back up - only thing is, while I was doing this, I broke my pump- seemed to split the plastic casing - and so I had to order another one to replace it.


Just make sure that you are not restricting flow to the intake side of the pump ...

I say that after reading several cautions from filter mfg's (Fluval, Eheim ?) about restricting the intake side of the supply, rather than the output from the pump.


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## HappyGrimgore (Dec 4, 2015)

I am going to scrap this project for now; the new pump i ordered came in, and has a hairline crack on the intake side of the pump - so it is going back as well. I could use it as a submerged pump with the crack, but would rather it be in-line. ( bad luck with pumps and amazon apparently!!)

I am probably going to buy a decent HOB filter for now, and maybe in the future if i stock my tank a little heavier, look into a sunsun or an aquatop canister...

Frustrating, to say the least as i've spend a good deal of cash trying this DIY stuff! lesson learned, just buy something proper to begin with, and soak up the cost. :?


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## somebody (May 13, 2014)

It's unfortunate your string of bad luck. Hope it all works out in the end for you.

Quick question....why inline? Any particular reason?


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## HappyGrimgore (Dec 4, 2015)

I wanted inline just so I can keep the pump out of the tank - clean up the look a bit, remove the heat source and cut down on sound.

check out my thread in the DIY posts, I have updated pics there!


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