I just got two mag 7s for my tank... my first mags. My other two powerheads are a Rio+ thats hanging out in my display and a Euro-reef for my skimmer. The two mag's have 4 big metal screws hanging out on them, which kind of surprised me. I'm using one of the powerheads as a return from my sump, so it'll be inline and not a problem... the other was actually gonna go in my display though. I know its not a lot of metal, but I'm still cautious... You guys all recommend the mag powerheads, so... is it a problem that the metal is there?

i dont know what a mag pump looks like, but id put a botom dollar that they are stainless screws if they are meant to be in water. if they are not stainless i wouldn't even consider it! keeping in mind even stainless will succumb eventually. if the pumps never going to see the likes of water, a quick smear of vasoline will protect the screws

Hmmm... I thought that they made the Mag Pond Pumps with steel screws and the ones used in marine had some kind of a corrosion proof coating or something. I'll take a look at my pumps at home.

Dave

Thats funny, I just got my MAG 7 and discovered the SAME THING. Whats the deal? I guess they coudl be stainless? Not sure. In other pics it looks like they used black plastic screws. These screws are on the inlet/outlet piece that would be removed for cleaning.

I posted on the marine depot forum and got an answer from one of their admins that they have ben using mag pumps with the metal screws for 10 years on reef tanks. So I guess it is safe.

http://forum.marinedepot.com/Topic48986-18-1.aspx

How very weird... they do look like plastic screws in the picture. I might do what the admin on the marinedepot forum said and just switch them out with nylon. Even if they are stainless, it seems sort of... strange that they would use them. Not like its hard to switch them out or anything :)

Mine are nylon or nylon coated. I called home and asked them to see if they were "silvery" or "black". The report was Black.

Dave

I think I will just switch to nylon as well.

They are stainless and I've been using them for about 10 years without a problem. I would not change them.

I used a polymer clearcoat spray on the srews when I had Mags.

for external use only right blub?

for external use only right blub?
Nope. Non-toxic, water insoluble, and corrosion resistant.

fantastic, i was not aware there was such a product that didn't contribute toxins indescriminantly

Hey guys I have only had my mag 7 for abour 1 year and I haven't seen any corrosion.

Hey guys I have only had my mag 7 for abour 1 year and I haven't seen any corrosion.
Stainless steel screws oxidize faster if it was subjected to saltwater and then allowed to dry atmospherically. If it stays submersed, the rate of oxidation slows dramatically.

I've used Mag 7, 24 and 36 externally and internally. No corrosion but they do add some heat. Especially the big ones.

Awesome! "Note to self do not remove water pump from water!" LOL

common problem with bigger pumps over there Amp, or just the mags. heat transfer problems are all in the design i believe

V, I should have clarified. Heat problem when used submerged.

I've used Mag 7, 24 and 36 externally and internally. No corrosion but they do add some heat. Especially the big ones.
Maintenance, and keeping your equipment clean will solve almost any problem.
common problem with bigger pumps over there Amp, or just the mags. heat transfer problems are all in the design i believe
what creates a heat generation problem is not the size of the pump, rather watts per gallon.
V, I should have clarified. Heat problem when used submerged.
That is only a given if your ambient temperature was lower than tank temperature, and if the airflow around an external pump is more efficient than the evaporative cooling surfaces of the aquarium.

Never had problems with my mag screws.

No problem with my mag screws either and it was in the sump for over a year. It was running my skimmer and when I got my new ASM skimmer with a Sedra pump I pulled the Mag. I noticed since I pulled the mag my cooling fans run less.

Brian

Wow... are your cooling fans on a thermostat of sorts? That's awesome!

D

Wow... are your cooling fans on a thermostat of sorts? That's awesome!

D

Yep, my cooling fans are controlled by a Ranco ETC Dual Stage Temperature Controller. They are fairly affordable compared to other electronic controllers, but all they do is control heat/cool. I bought mine used from a guy that wired it with two outlets for cooling fans and two outlets for heaters along with indicator lights on which one was on.

I have it set to turn on the fans once the water temp hits 82F and the fans turn off when the water temp hits 81F. The heaters kick on when the water temp hits 78 and turn off when they hit 79.

It has been a very reliable piece of equipment so far, approaching two years of use. I debated about getting a more expensive controller with multiple things it controls, but I'm very happy to control my own pH and lighting cycles with timers.

More info on them:
http://www.automatedaquariums.com/ranco.htm

And no I don't work for them, just like their product :)

Brian

I'm wayyyy jealous! Good for you bro!

Thats not a bad solution.

Still i am looking for something under $50. More like $30 would be good. But I only want to control fans. I have a couple circuit diagrams to work on that might do the trick. If anyone has done this or knows of something else I'd be happy to hear about it.