Hi, brand new to the hobby, well saltwater that is. Anyways, I have been trying to research all different types of overflow systems before ordering my new tank. Just wanted to hear some thoughts on which is the best type of overflow system to use. I planned on having a 100-150 gal mixed reef tank.

Basically, what are the pro/cons to each, and how does a person calculate how much water (gph) each over flow will accept at maximum so I match it to my pump or vice versa.

1. full tank height center/corner overflow, 1 or 2 ?
2. small box in corner overflow
3. hang-in-the-back overflow
4. full back tank overflow
5. typical over the top CPR type overflow

When I get my tank drilled I want to do it right.

Any thoughts would be appreciated. I haven't made it through all the podcasts yet, but if my question is answered in one of those please direct me there or to a thread I might have missed. Pretty loaded question for my first post I know :eek: thanks so much.

nanopodreefer,

http://www.theculturedreef.com/welcome.gif to Talking Reef Community.


If you go to Reef Central (http://www.reefcentral.com) and look down the left column you will find a heading titled "Calculators". The answers to many of your questions about reefing will be found there.



Dick

Hello, I am new at this stuff too, I just ordered an HOB overflow from Lifereef Filter Systems (http://www.lifereef.com), I have read a lot of negativity about the CPR and Marineland overflows with Flooding. Supposedly this is one of the better ones on the market.
I have 125g mixed reef myself. But if you have not installed the tank yet, I understand that drilling the tank first and having a bulkhead attached with strainer is the best type of overflow to have for a sump drain. The drilled option provides the least amount of chance for a flood to occur. It was too late for me as I was too excited to setup the tank and fill it with water.

Good luck on your decision, this is a great forum

Now to more directly answer your questions.

Basically, what are the pro/cons to each, and how does a person calculate how much water (gph) each over flow will accept at maximum so I match it to my pump or vice versa.

1. full tank height center/corner overflow, 1 or 2 ?
2. small box in corner overflow
3. hang-in-the-back overflow
4. full back tank overflow
5. typical over the top CPR type overflow

When I get my tank drilled I want to do it right.Referring to your tank size 100 to 150.

1. Best option, number of O/Fs dependent on tank turn over and O/F design. They say a 1" drain will handle 700 gph. As a safety measure I use 600 gph. If you want one O/F make it wide enough to accommodate two or more 1" drains. I like dual O/Fs with dual drains for either of these tank sizes.

2. Totally inadequate.

3. Totally inadequate.

4. An option but, overkill and wasting space.

5. Not on this size tank. Also, prone to failure, causing overflow of water.

Hope this helped.

Nanopodreefer, welcome!

My personal opinion is that people rely on the overflow->sump->return loop too much for circulation in their tank. I have seen increased success with my tank by increasing the dwell time the water spends in the sump so that my skimmer can skim that water several times before it returns to the tank. My overflow gets relatively low flow and probably turns the tank over maybe 3 or 4 times an hour, I think. I then use flow pumps (Seios in my case) to provide the in-the-tank flow that's critical for a healthy tank. 2 Seio 620's in my 25g tank are perfect. I can't take credit for this idea, of course, someone waaaay better at this hobby than I am wrote an article on it and I read it. Can't remember where unfortunately.

If I had your oportunity (and funds) to pick and choose:

1 full tank height overflow in the back center of the tank about 1.5x-2x as wide as an All-Glass megaflow.
Tripple drilled at the bottom of that overflow. 1.5" hole(or whatever that max size bulkhead is) overflow, 1" return, another 1.5" overflow.
Tunze Stream pumps or, on either side of the tank, I would have two holes drilled for a closed loop system to provide main circulation in the tank.

My rationales:

3 complete sides viewing (albeit short sides with a typical tank)
Plenty of overflow for no clogging, but no massive return pump needed (power savings, price savings, etc).
More dwell time in your sump for your skimmer to do it's work and/or a refugium.
Still have good circulation in the main tank.

The problem with internal powerheads/pumps is... well you can see them. I know some peeps are like me and would rather put 50 million holes in the tank for a CL than put one pump/PH inside the tank. Just my preference.

Just to add my 2¢.... I was amazed at how easy it was for me to keep my tank in the mid 70's F after removing all powerheads and pumps. Instead, I opened the existing Mag7 full throttle and used a manifold system to move my water. With the Maxijets in there, I couldn't keep the temps below 80F.

Dave

I guess, for "history" I should explain to anyone who does not know me...that I have a Hippocampus Reidi system that requires my needing to keep temps below that which is considered "Reef".

Dave

Just to add my 2¢.... I was amazed at how easy it was for me to keep my tank in the mid 70's F after removing all powerheads and pumps. Instead, I opened the existing Mag7 full throttle and used a manifold system to move my water. With the Maxijets in there, I couldn't keep the temps below 80F.
I quite agree on the heat transfer issue. I ditched my Maxijets for Seio's this summer and come winter, I had to buy a stronger heater than the one that worked fine last year! I'm looking at a system to get my Mag up out of the water in my sump for next summer.

I think the problem is Maxijets, though. I love them for utility jobs like salt mixing or water changes, but for flow volume in the aquarium, they aren't very efficient. The Maxijet 900 is rated at 8.5 watts, but pushes only 230gph (the 1200 is 20w and only goes to 295gph -- go figure), but a Seio 620 is doing 620gph for that same 8w. Tunze goes even better, albeit for alot more money, at 1600gph for 11w. Money is an issue for all of us (unless we've got a few millionares out there), however, so Tunze isn't an option for all.

hey thanks, for the quick reply and indepth answers, one of the reasons that causes me to wonder why it took me so long to find this site ;) lots to think about and evaluate, thanks again guys.

Je vous en prie!

Hi nanopodreefer,

:welcome: to TR.

I have read a lot of negativity about the CPR and Marineland overflows with Flooding.

I'll mention a little of my own experience with a CPR overflow. I really liked it, and I still use it...however I did encounter a problem. One will need to keep an eye on that little nipple fitting that is used to draw air out of the overflow. I've had the glue that holds it in place give way on me a few times and caused small air leaks that allow air into the overflow siphon area and will eventually break the siphon....causing a flood. Thankfully I haven't had it flood on me, I've caught it before that has happened...but it's happened to me around 3 times now (first time wasn't my fault...next two were as my regluing just wasn't good enough).