Pump size, lets get this debate over with!!! Everybody's two cents wanted!!!

[GuyBFF]

How big is big enough for the Pump!!!!!!

OK, I'm running a Danner Mag-Drive 250gph and I know someone who wants it for a fish tank, so it's time to consider if it's worth upgrading (as it will hardly cost anything)!

Here's what I have:
AMD 1.333ghz @ 1650 1.95v
Danger Den Maze 2 with 1/2" fittings
Inline setup with 1/2" Braided PVC (just upgraded)
Surplus 4-Core 5" x 7" Cube (Like the Danger Den or Aquacoil) I've made two flowpaths as the tubing is 3/8" (sorta what BE did)
120mmx38mm 107cfm Delta Radiator Fan

Everybody recommended a 250gph with the 1/2" tubing, but since I saw a large improvement from 3/8" to 1/2" tubing, do you think I should also go to a larger pump. Locally there's Danner Mag-Drive 350 and 500gph, or I could just stay with what I have.

Also where does everybody feel the sweet spot for the pump is and when will it start to heat the water and sound like a bulldozer?

Hey keep this open too. Please add your own thoughts and experiances even if it pertains to a different setup!!!

[stevo]

despite the pumps ratings ,you'll never achieve anything even close to it simply because its restricted by the smallest ID. of any part within the system.
I'm of the opinion that a bigger flow rate achieves hardly anything because the old car radiator thermostat debate...enough time to cool down whilst passing thru it etc.
I did try on my setup a car windshield motor pump.Man that thing really squirted water thru the system and the results?Nothing thats what I found.The best solution for cooling I found was mounting a peltier over the cpu.Ok despite condensation issues which I have taken precaution against.Pumps,radiators,hose sizes,chill tanks,water mixture etc etc just don't become an issue anymore whilst achieving the best possible results so far.
Ok thats my view....
L8er stevo

[GuyBFF]

I would tend to believe this as in motocross racing we didn't use a thermostat, but modified washers to find the coolest temperatures, and therefore most power. Almost every benchmark I see though, people are commenting "next time I'll get a bigger pump like - 500gph", etc. I already have pretty big 250gph, but I can upgrade for aboout 10.00 so I'm just trying to see what the general idea is, and I appreciate the reply!

[TNT2bluz]

More is always better.

The only concerns you would have would be the fittings being able to handle the added pressure.

I can't find that darn URL.

[dantheman]

I grabed a 500, and it will heat the water if you don't keep the fan running.

[nportelli]

You do not have to worry about added pressure from upgradeing to a larger flow. And the temperature add is minimal. Especially if you do not have it submersed. I have a 900gph pump on my fish tank and all my tubing is just dry fit no clamps. Not once has it ever leaked.

[GuyBFF]

I've already installed a dozen hose clamps just in case I push a hose off somehow, so I shouldn't have to worry.
Is there a lot of noise increase between the 250 - 350 or maybe even bigger (how bad do those 700 / 900 bad boys sound)? I'm trying to keep it all down a little.
The nice thing I noticed is the 250, 350, 500 and 700 are all the same physical size for the Mag-Drives, so it's going to make a swap easy once I decide how big I should go.

Thanks again for the reply's, it's strange how some say no improvement over 150 gph, some say 250 gph is the sweet spot, and others say you can't have enough - 500 + gph. I thought I had the pump pretty figured out, but nobody seems to agree with anyone else! Let's fight this out!

[JimS]

I think it all depends on the radiator that you are trying to push water through. I use a heater core(basically a Big Mama) which requires a good size pump just to keep it from accumulating air pockets at the top. I have a Danner 500 in my main system. Originally I had a 250, but it was not pumping enough water to get the air out of the rad.

BTW, I have never seen the front seal leak in any way, or the threaded outlet. Never touched the pump with caulk or RTV sealant, has never leaked a drop.

[GuyBFF]

JimS how is the noise differance between the 250 and the 500 Danner Mag-Drive, there the same size case so I assumed the impeller on those bigger pumps had to be just screaming?

[mkosem]

well, what is the head danner is talking about when they specify 250gph? I suppose this would have a lot to do with determining the actual flow of the system.

--MAtt

[GuyBFF]

Danners Mag-Drive advertised flow rates are at one foot head (I think this is the same for most of the pumps).

[GuyBFF]

I think I'm going get the Danner Mag-Drive #3 350gph unless someone else has some updates.

I'd like to thank www.overclock-watercool.com and www.highvoltagepc.com. Both of them replied to my emails and where very informative. They both said 350's are about what I need. Hopefully I'll see improvements over the 250.
Anyone else have 2c to offer? Still Open

Also I think I'm going to ditch the home made cube (which was a copy of the BE AquaCoil) for a Big Momma, there only 49.00 now and from what I hear the rad core style is the way to go.

I'm assuming the Big Momma (bigger, thicker) is a better cooling core than the Black Ice, any opinions???

[JimS]

Once you get all the air out of the system, the 500 Magdrive is virtually silent.

[mkosem]

um, the EHEIM 1048 is rated @ 158gph with 4'11" of head. I don't know, I'm happy with the performance of my system and this pump.

--MAtt

[GuyBFF]

I could be wrong, but the head hight of 4'11" on the eheim 1048 is the max delivery head. 158gph is rated at a head of 1'. This os how it's listed at my local fish shop.

[mkosem]

ahh yes, you are correct. But if most pumps are rated @ 1ft of head, how come this RIO180 is such a piece of crap? Or is it rated @ no head?

--Matt

[GuyBFF]

If I'm not incorrect the Rio 180 flows 120gph @ 1ft.

Problem these ratings have is understanding using gravity as a "restiction". In your system gravity has no effect, as water is siphoned up by the water going down (conservation of mass), and it doesn't matter if there's six feet up to down, or two.

The real problem is the restrictions (3/8 fittings with 1/4" ID) and just water travelling in the tubes, etc. This is where the restriction comes from.

A good pump like the Eheim you purchased may flow near the same @ 1ft, but once some restriction starts to allow them to cavitate, the better pump will win by far. For instance two pumps can be rated the same @ 1ft, but @ 3ft one might flow half it's original rating, the other might hardly flow at all.

Now I said the height didn't make a difference, it doesn't, but the ratings are just the easiest way to relate how the pumps will deal with back-pressure (restriction). In a pond the water is pumped straight up, with no aid of water returning down. If you put a pump rated at 4' max head, it will do 4' above the water line (even if it's two feet submerged from the pressure of the water)

Get it?
Problem I have is deciding what's ideal.

[imagex]

I would not want to use anything less than a 500 gph pump,i made my own block that is 5/8 flow all the way and i use 5/8 lines, i found that the larger flow works better. 750 duron @ 1000 mhz, 1.85 core, 120 watt/24 v pelt ,500 gph pump, evap cooler= 27f at idle. works for me

[JimS]

Don't forget the restrictions within most waterblocks themselves. For example, the Maze2 block has a total of 12 90 degree turns, and two 180 degree turns. Now that is what I call restrictive.

Not trying to start a waterblock debate here as I know many people use the Maze2 and get good performance.

[GuyBFF]

Waterblock debate isn't a bad idea! It seems there is fear of debating on ProCooling. All the regular posts are newbies that haven't read the previous posts asking what is a recommended system. There isn't much in the area of experienced debate. Cone onlet's start fighting!

[simon]

Ok , heres the bascis. A higher flow rate means less time to lose haet in the rad BUT the water is in the water block for less time so it picks up less heat say per mililitre. This evens out roughly. With a higher flow rate you will get slighlty less heat per mililitre being gained by the water but your are increasing the amount of water going through the block. HIGHER FLOW RATE IS BETTER. I think the guy who said pressure doesn't matter is wrong. Just check with where you are buying it how much pressure your dealing with and what precautions to take.

[Mr Kneecaps]

I agree with Skippy in that the amount of heat being moved (thinking in terms of time) hasn't changed with different flow rates, just it's spread through a (larger) volume of water.

And the whole thermostat thing - thermostats are designed to keep an engine at a specific temperature - not the lowest possible temperature. I can maybe understand this in a peltier system to reduce condensation.

If you need to restrict the flow of water through your system to allow the radiator to remove heat then I think that the radiator must be too inefficient for the heat being generated. Within sane limits.

Not a flame, just my opinion.

Kneecaps

[resago]

this thread was 5 months dead for a reason.
buy an eheim, install it, and don't waste another second thinking about it.

[ 12-19-2001: Message edited by: resago ]

[Kevin]

Originally posted by resago:

buy an eheim, install it, and don't waste another second thinking about it.

Hehe amen to that

[Mr. Thompson]

The 250 and 350 are the same pump. The only difference is the impeller which you can buy for about $7.

Danner pumps are rated at 0', not 1'.

Before changing your pump, try putting a hose clamp on the output to restrict the flow. If your temps go up, a bigger pump may help. Tuning the flow to find the sweet spot is a must with any watercooled system. Before I switched to a bong cooler, with a Maze 2 (origional version) and a Cooling Cube, a Mag 7 with unrestricted flow gave me the best results.