External Overflows
 

Just a quick question on cpr overflows or any external overflow for that matter.
Are they okay...i mean i know having a tank drilled is the optimum, but if that is not an option with a tank are these the way to go? or is like an enheim wet/dry a better choice? instead of an external overflow with a sump?

Are the people if they are using an external overflow...suitably happy with them?

I've heard the good and the bad about these things, but I'll tell you about what I've dealt with using a CPR50

They Work. However, you do need to watch the siphon which on my model tended to clog with crap every once in a while and the overflow would lose siphon and well, you know what happens after that.

I've since stopped using my CPR50 because I won't be able to tend to the siphon every day. I guess what I'm saying is if you don't have the time to genuinely watch it every day, don't use it.

Personally I've had a whopping single problem in a year running a DIY'd (actually bear27 diy'd) weir style overflow. And that was my own stupidity, failed pump + failed top-off = big microbubbles problem.

If you do go with a CPR, get the one with the TOM aqualifter pump, 100% more reliable than a powerhead/venturi. Personally I'd avoid the U-Tube style as they have no ability to clear bubbles which could get into the tube.

Andy

Another question.....is it possible to have a succesful reef tank without a sump?
What i mean is what is the next best thing to a sump...like an enheim wet/dry?

If i put say two canister filters on a 70 gallon tank would that be sufficient?

Many people have had success without sumps. Bob_I and Beverly are a couple of gurus in this type of tank.

I have a 35G sump on a 70G for two reasons only.
1 Unsightly equipment(heaters, powerheads, big skimmers) disappear from the display tank
2. Water volume. By adding the sump I now have more water, ergo, less can go wrong. for example if the water level drops an inch in the sump, the salinity won't skyrocket like it would without that extra water volume.

Some people add things like refugiums (good to have also) and other types of filtering etc, but IMHO Sumps are the kats a$$ for a display tank you want to show your friends.

You are kind of making a mistake by assuming sump == filter. The way a lot of people use sumps in reef tanks they are not really working as a filter. The good parts of a reef tank sump are like Gizmo said. Not all sumps have built in trickle filters and most people who do have a wet/dry trype of thing going on end up getting rid of them.

A filter is not a strict requirement for a reef tank, it can actually cause problems. If you are starting with a good ammount of live rock and a skimmer you won't need it. Your biological filtration happens on the surface and in the crevices of your rock and you are not going to need mech filtration because you don't (shouldn't) have many fish and your clean up crew will get to the left over food. The skimmer will get the disolved gunk for you. You can actually end up having too much crud build up in a canister over time making it impossible to control nitrate levels.

The thing you need in a reef tank is water flow, most people overlook that at first. You can acomplish water flow much better with a couple of powerheads than you can with a canister. You can also get about 3 SIEO 620s for the same price as a single Fluval 404.

So spend that money on the best skimmer you can get (for hang on the Remora is good) and a few big powerheads.

so i should do this, if it's okay....

72-70 gallon tank
2-3 inches substrate.
can i start with say 30-40 pounds live rock and add more..(before i add any fish or coral or anything of this nature) Then add more every couple three weeks....
use my XP2 for mechanical filtration/water polishing when needed....
and a sump as more of a refugium...?
then get a skimmer as soon as i can...
Just trying to plan if i can get some things going while waiting on others till i can get the funds...or to get it all before i start.........
hmm....
will a 24 inch PC light 130 watts be sufficient for a FOWL untill i can get the nice biggy for corals etc....i think it should be....maybe have wierd lighting effects being only half as long as the tank....hmm...

Don't delay on the purchase of the skimmer. I wouldn't start up unless you have it in place. Yes, it is that important.

This is in another post too, but if you are getting a new tank, get it drilled for an overflow, and preferably for a closed loop.

You don't need a trickle filter, or wet-dry, or canister. In the sump you can hold your heaters, add more water volume, put a refugium into it, and is a good place for an auto top off.

This is not true. You can drill a hole in the top of the u-tube and install a 1/4" airline to let air out. And a u-tube overflow can be very safe if implemented correctly.

1. If the siphone quits, what happens? Your return pump keeps going, and empties just the return section of your sump into your tank. Make your return section small enough that your display can take the extra water, and there is no way to flood.

2. But then your pump will burn out, if this is a big concern, install a float switch to kick the pump off if the water level gets too low.

3. Make sure the model you buys keeps both ends of the u-tube sumberged if the power goes out, this way siphon will not break, and flow will continue when power comes back on.

4. Block light from getting ot the overflow, this way nuisance algae will not grow as much and potentially clob things up.

5. Regular maintenance, if you have done the above, weekly should be more than enough.

Those reccomendations are for those with setup tanks who are running an external overflow already, or who want to add a sump without disturbing their tank. If you are starting a new tank, get it drilled like swiss cheese and you will be happy you did. If you are handy, you can order diamond hole saws from hongkong for less than $5 a piece shipped to your door, and drill yourself.