Internal/External return pump...

superwizbang · 05-29-2006, 10:34 PM

Hello all,

Instead of side-tracking my sump thread, I thought I would ask the question here. I currently have an Iwaki 40 external return. My question is this:

I will be using the Iwaki to push water into my new ETSS downdraft skimmer (recommended pump). I am designing a new acrylic sump and am torn between plunging for another Iwaki return or going internal and having a mag 7 or 9.5 do the work. How much heat will I actually see in a 120ish total volume setup between internal/external?

I know there is a difference...but *really* how much? This would be a money savings...but I would rather do it right and spend the money if that will be the best route in the end. Also, will a mag 7 closly equal the output I currently get (yes, I know Iwakis are better rated for pressure) with a ~4' return to my display? Should I opt for the 9.5? The current flow that I have is about right and just want to stay about where I am.

Thanks in advance!

-Ken

fchidsey · 05-29-2006, 11:32 PM

I prefer external pumps my self i think they keep the tank cooler and are more reliable (no broken mag drive impelers) things of that nature.

However I run a mag 12 that powers the return to the tank and tees off to the uv and chiller I have good flow through the tank. (I don't know how many gph.)

motorslave · 05-30-2006, 09:01 AM

I also prefer externals. One is the heat, amount depends on the pump and Im not familiar with Mags. The other is the noise issue and vibration. Also with an external and a ball valve you can remove the pump if needed without fighting hoses and such. A good external will cost more but I have yet to find a submersable that compares to an external. JMO

Robert

motorslave · 05-30-2006, 09:01 AM

duplicate post

Wiskey · 05-30-2006, 10:09 AM

Mag pumps also have that nifty rusting screw issue,...

I would go with the Iwaki hands down, it is a more reliable pump, keeps heat out of your system and deals better with head hight.

The other thing that worries me is that the more things I have in the drink, the more chance for a failure that electrocutes me or my critters.

HTH,
Whiskey

Tim224DT · 05-30-2006, 10:27 AM

I like external pumps also (Little Giant) and yes mag pumps have screws that tend to rust over time.

Tim

superwizbang · 05-30-2006, 06:33 PM

Thanks crew. The way I was leaning, but wanted a "fuzzy" on my thoughts.

-K

motorslave · 05-30-2006, 06:36 PM

Also if you go external you may want to consider the Gen-X PCX pumps. Pretty quiet and work great.

Robert

Geoff · 05-30-2006, 08:03 PM

what size tank is this for again? i would go with the iwaki and stick an eductor on the outlet. now we will be talking some real flow.

G~

superwizbang · 05-31-2006, 09:39 PM

It's for a 90g

dobejazz · 05-31-2006, 09:51 PM

If you havent made up your mind check out Vinces thread
http://thereeftank.com/forums/showthread.php?t=74960

VWD · 05-31-2006, 10:01 PM

Go external. I wish I would have had all mine external. The cost may be higher to do it, But will save your grief down the road maybe. I have done both for years and this was the first time it happened to me, It may just be a rio thing.

superwizbang · 06-01-2006, 11:41 PM

Vince, I think that seals the deal. I had heard that about RIOs but never heard something like this happen to someone. I can get an external pump at near cost and think that might be my route. Motor, it may well be a Gen-X. I will see what I find on eBay. That is where I got my current Iwaki with good results, but I would like to get this in this weekend.

-K