do you really need two overflows on a 180?

[hdking]

im doing plumbing on my new 180. 125 was my last tank. i was told i should run two overflows...one as a backup. how critical is this? id like to know before i have tank drilled. thanks

[dave.m]

It depends on what type of drain you want. If you go Durso you only need one. If you go with a Herbie or Bean Animal types they recommend two or three. These are all co-located in one overflow.

Dave.M

[savethereef]

Its the difference between a flooded. Use one as a main the second as a back up. I have three on my 450g on my 225g had two. My 180 wish I had two

[fng_71]

It also depends on flow through your sump. I have a reef ready 120 which I removed and capped one of the overflows. I'm going to use the other overflow with 2 dursos. One main one emergency. I only plan on running about 500 gph through my sump. A 1" durso is rated for up to 600 gph. I'll have a 3/4" sea swirl return. My skimmer has a 600 gph pump so I don't want to exceed that

[ca1ore]

Do you mean two drain pipes behind a single overflow, or two overflows? I ran a 180 for almost 20 years with a single overflow and surface skimming was fine, but I did employ dual drains (herbie before it was called herbie) and wouldn't even consider running a tank with only a single.

[leveldrummer]

Use multiple drains in a single overflow. no need for extra overflows, but you absolutely want more then one drain line, 2 at least, 3 is best to avoid floods.

[hdking]

yes i was thinking two 1" drain lines from one overflow box. my return pump is a mag drive 12 and has 5 1/2' head highth

[NewMariner]

I had a 180g with a single overflow but had a 2 inch drain. It worked just fine however I had to put a return line on the opposite side for more flow. That kind of defeats the purpose of a single overflow in my opinion. I'm a very symmetrical person though..