Overflow for AC 500

[FishF00d]

I recently thought about adding a 10 to 15 gallon nano to my collection of tanks. Can I call it a collection if i only have a 135 reef tank right now..?

Anyway I've seen some of the setups people are running and it looks like the AC500 for a fuge is a great idea. I've seen how many people do not like the surface skimmer that you can add to them. I also like the idea of hiding a ph behind a false wall/wier/overflow.

I had wanted to put this false wall in like a normal corner overflow box so that the return from the AC500 goes back into the tank, not the overflow. What I'm really wondering is if the intake tube for the AC500 would work in the overflow. I intend to put a ph(for extra current in the tank) and float in there as well for auto top off. That would keep the water level in the overflow area high enough so the AC500 doesn't loose suction.

Does this sound like it will work?

[Agu]

The concept would work , look at the surface skimmer sold for bakpak skimmers,

http://www.drsfostersmith.com/product/prod_display.cfm?pcatid=4423&N=2004+113771+2146962038

that could easily be adapted to an Aquaclear.

[FishF00d]

I thought it would but wasn't sure if enough water would flow into the AC500 and a powerhead similar to the little ones that use to come in the IO buckets. Wanted to hide everything and figure that would be the best way. I'd just put some lockline on the output of the powerhead, through the wall of the overflow.

That backpack skimmer would would also if i didn't want to hide the power head and float for the topoff.

[dantodd]

It will stay full enough because level is determined by how much water is in the tank.

The amount of water pulled by the intake is exactly equal to the amount put back in by the AC500. Only issue would be if you don't have enough inches of overflow for the volume of the AC500. I think 2 or 3 inches of overflow would be plenty but I'm sure someone has calculated actual flow/inch somewhere, might try searching when you can.

the other problem you might run into is that all of your evaporation would end up in the overflow. This means if 1" of total tank area evaporates and the overflow area is 1/10th of the tank area your overflow will be down 10" and the tank will still be full looking. All this means you will have to be more diligent with your top off. Auto-topoff is really really good idea with this kind of setup.

[FishF00d]

didn't think about volume for evaporations. I was looking at it from the angle that since there will be less volume in the overflow the water salinity would not fluctuate since fresh water would be added often. I'd probably keep a 5 gal bucket under the tank.

How much would one of those AC500 evaporate a day? I'm currently filling a 18 gal tub ever few days on my 135. I would imagine that a 5 gal bucket would support a small tank like that for at least a week to week and a half.

[dantodd]

I may be mistaken, I thought you were going to create an overflow box. Just for an idea, my 20L with 220w of PC evaporates about 1/2 gal/day. In a 20g tank that is 12 inches high I will see about .3" of water level drop in a day with the 20 gal. If you are using an overflowbox to feed an AC filter the waterlevel in the AC and the tank will be constant and all 1/2gallon of evaopration will be from the overflow box. Does that make sense?

If the surface skimmer you are talking about doesn't work like and overflow then I guess it won't matter.

[FishF00d]

That was the plan... an overflow box. Normally I would expect the level to drop in the sump/fuge, whatever is there, but for some reason I would think that since the AC500 will suck up the same amount of water at all time the level would drop in the overflow box. The tank would remain the same becuase of the fuge dumping water into it and the fuge would be the same because of the rate of flow from the uptake. The overflow area would go down. As the water being sucked up is a constant and the amount that is in the main part of the tank is a constant wouldn't any evaporation lost be noticed in the overflow?

[dantodd]

Exactly. That is what I was trying to say. I had thought from your last message that I had somehow misunderstood your layout.

Are you planning on running an auto top-off? That would eliminate the problem of excess evaporation and, as you suggested, minimize salinity swings. I think that is the difference. I don't use an auto top off so that's why I thought you might run into the problem. I would expect 5gal to last atleast a week, assuming you are running similar lights. If you're running 1000w of MH for 18 hours a day it might be a little more. :)

[FishF00d]

How much flow do these AC500 create in small tanks? Would I be able to just ditch the ph? I mean my 135 is BB and I have a blue line 55hd as the return with penductors and a reefflo dart on a closed loop. Unless its glued down or attached in some way it will end up back behind the rockwork or lost.

I just don't want to have any dead spots in this little thing and before I go out and buy anything I want to figure out what is really needed. If the AC500 will create enough current then I'd just stick with that surface skimmer attachment that you suggested.

I misread what you wrote. I thought you said the water level in the AC would fluctuate, not the overflow.

And yes I plan on a top off unit. The float switch would be in the overflow if i go that route.

Whats wrong with a 1000w bulb over a nano tank. :) Thats more then my 135 has.

[Sugar Magnolia]

AC 110 (500) is rated 500 gph. IMO, it would be a good idea to add a small PH to help randomize the flow pattern. If you just stick the AC 110 on for flow, you'll have the same circular flow going, with a pretty good chance of having some dead spots. Stick a microjet or that little Tunze powerhead in there aimed in the opposite direction that the HOB will be flowing.