Submersable vs External which way you go??
 

OK, I am wondering the pro's/cons on Submersable and external pumps. I know External needs a bulkhead fitting on sump, but why would one choose one over another? Do submersables have shorter lifespan? I am thinking a Mag 18 for my Sump, but then, I could go a little more fro flow. And it isnt that much more to jump to external for as far as the pump costs.

Just wondering why you went with the pump you did??

in or ex
 

I had a chance to look at a Sequence Reeflo Dart working before I set up my new tank and based on how quiet it is, the amount of water it moves, the amount of maintenance involved, the low power consumption, and the lack of heat transfer I chose this one. Until now I used submersibles and never had any problems so I'm starting to believe that if you don't have a huge tank it's just a matter of personal preference.

One of the big reasons I think people go for the externals is heat issues. Personally, I went for a Hydor Seltz L45. Low power, good flow, good price. I'm running it submersible because I seem to have the opposite problem... my tanks in the basement and I struggle to keep it close to 80, most days it's further down in the high 70's so I'm after all the heat transfer I can get!

You can calculate the heat rise

Temperature change = Total watts of your pumps / flow rate of all your pumps (in grams per second) x 4.19
This give an aprox calc. Please correct me if I am wrong.

My vote is for Ehime submersible
Quiet and reliable, low watts high head

I would recommend going external if you have the space. I think you can get a more efficient pump. It also gives you more room in your sump for other things. Even with a 90 gal sump you always with you had more room available.

The main reasons for external are HEAT, HEAT and HEAT.

Oh yes and then there is Quieter and more Flow.

Tom R

Eheims can be run externally, like my 1260. It's great and much easier to do maintenance on provided you hook it up with true union ball valves.