recommendations needed for drains/returns for 300DD

airtime23

New member
Hi y'all!

Need some advice on the plumbing for a 300DD.

The tank has two corner overflows, each with 2 drilled holes in the bottom.

Now, my question is:

Option 1: Should I use each of these holes, 4 total, for drains into the sump? If I did this, I would have the returns coming back to the tank "over the back".

Option 2: Or alternatively, should I just use two (one on each side) as drains, and the remaining two (one on each side) as returns?

The only reason I was thinking of doing option #1 is for higher flow, especially since I want to keep SPS.

Any recommendations? Thanks in advance.
 
I personally would (and did! on a different sized tank) go with option 1. Reason being is redundancy.
If you did option 2, and one pipe clogs, that means the other pipe deals with all the flow, now if these are large diameter pipes (you didn't state how large the pipes would be) the one pipe may be enough to keep the flow going fine, but what if it's not? You get a not-so-pleasant situation. Now even the other pipe was more than capable of handling the flow what if you don't notice that pipe one is clogged? Then pipe 2 gets clogged? Same issue.

Also I've noticed with my pipes (beefy 2 inch wide) that with the overflow covers on I barely hear the water going down because the size of the pipes is very large compared to the amount of flow going through, no slurping, no sucking, no gurgling, basically everything that people use any number of creative "pipe bends" to try and combat (herbie, etc). Now if I remove the overflow covers sure I can hear the sound, but still no "late night at Taco Bell belly noises".

One last thing to consider, and I had this on another tank where I basically did option 2, and is something I did not take into consideration. If you were to have a power outage (something you always need to plan for) the water drains to the bottom of return pipe. Now you might say "so what a siphon on a pipe over the edge does the same thing", but when I've had pipes over the edge the output is never as low as a hole in the overflow comes out, and once it starts sucking in enough air it does break the siphon. With the overflow returns it's basically water flowing "downhill" so a considerable amount more water drained (and in my case, my sump was not large enough and much hair got pulled in frustration)
 
Some people really push the idea of increasing the amount of water your system drains. However, that's not necessary. You definitely want increased flow in your display, which you will want some powerheads that can give you strong random flow, but you don't really want stronger flow through your sump. You want a good amount of contact time through your sump to allow the water to be filtered properly, along with keeping your system more stable. I'm sure this will cause debate, but there are many articles on this topic that go back a lot further then the ones you find on full siphons. This being said I am speaking from experience, I have run both systems. I was caught up in the hype about more drains more flow.. Now I do like the idea of having an emergency drain, but I have seen no other benefits. In fact I find myself constantly worrying and tweaking the flow rates. Extremely annoying. So in my opinion, I would setup your 300dd as stock and focus on creating strong turnover in your display, not your sump. On top of that you will spend less money on energy because your return pump isn't pushing as much water, and you should then be able to get a smaller more quite return pump. I suggest a reeflo dart hybrid for a dedicated return pump, they are awesome.
 
To be safe go with option 2.

If your weir fills up with a sudden algae or anemone or other item, at least the other side will still be running/draining. There is nothing worse, speaking from experience, to turn around see water dripping all over the floor to only look up and realize that a line was clogged and the other drain was not setup yet (snails loved to see where they could NOT fit)

Luckily this was a quick fix, as I was just doing some maintenance. Really glad I was at home and did not have to worry about a house sitter skipping a day because I would not notice.

So YES, standard drains as you said in option 2.

Turnover rate from sump to DT is important but more-so is internal flow. Some people use powerheads some people re-drill their tank and make a closed loop.

I have a dc12000 for a return pump. I can adjust the flow and dwell time in the sump.
 
Well, clear as mud!

2 people are for option 1 and 2 people are for option 2....

Thanks for clearing it up for me, fellas!
 
Flip a coin. It does not matter which option you select. Water movement will be accomplished by powerheads not return pump.
 
Depends, really, on how much flow you plan to have through the tank. I subscribe to the 3x tank turnover per hour, so you are looking at a bit short of 1,000 gph. Assuming you go with option 2, that's not giving you all that much headroom. ML says you can push 700 gph through a single durso, but that is max and very noisy. Figuring you are better off with something like 350, which means that just two drains ain't gonna cut it. Further, I would NEVER setup a tank without a backup drain (or two). What I would do would be to configure each overflow as an independent herbie, and either punch a hole in the back panel for return or go over the top (an aesthetic compromise, in my opinion, so make sure to use black PVC). You really only need a single return because as noted earlier in tank power heads ideally provide varied flow.
 
I have two overflows on my tank with two 1.5" holes in each box. In each box one is a dead silent durso drain and the other is emergency for clogs. My returns then come over the top and I'm probably pushing about 1500 gph thru the tank. I am very happy with the way this has turned out.
 
I currently have a 110 show tank with a small sump. I spent days trying to figure out how I am going to plum my 300DD with a 75 gallon sump. Im going to go with the same set up I have now on my single overflow. I took a 1 1/2 inch pvc for my drain roughly 6 inches from the bottom of the pipe I drilled well over a dozen holes in the drain pipe, then slid something like one of these http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4182 over the top of it. It cuts down on the noise and is a great pre-filter and I believe is going to be much easier to clean then the filter socks.
 
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