hob overflow/display fuge?

[Riona]

I'm thinking of setting up a display fuge to grow some macros/house the pencil urchin that came with my LR since I've read he'll eventually not be reef-safe, and since I don't have a drilled tank (nor do I trust myself to try to drill it) that'd mean some sort of overflow.

King of DIY has a PVC one (the upgraded sort) that looks easy enough to make. Do those actually work as advertised? He claims the updated one won't ever fail in the event of a power outage, but is that really the case? I'd hate to be at work in case of a bad storm and have my pump die over a couple days running dry.

Otherwise it's the CPR/eshopps type. I've had one of the latter before, and I couldn't ever get it to stop gurgling. I've read that that's too much flow AND that it's too little. Assuming that sort would be a safer bet, what could I do to make it not be so loud, since I sleep in the room my tank's in?

Last question. I know you can make a return pump too big, but can you make one too SMALL? If, say, my overflow could handle 500 GPH, but my return pump would only be putting 100 GPH back into the tank, would that kill the overflow, or would it just be that it'd overflow the 100 gallons and that's that? Still not sure how much flow I'll want through it, but if I can find an overflow that does X gallons an hour, I don't want to leave it breaking siphon constantly due to the return being too small.

 

[Reefing102]

@BeanAnimal any help with this one? I don’t have any experience with external overflows

 

[Vinny Kreyling]

The Best one is a Lifereef unit.
My suggestion would be a DC pump because of its variable flow.
Too little flow could mean a surge ever once in a while, or you might get lucky & everything just works.

 

[Riona]

@Vinny Kreyling The Lifereef looks nearly identical to the eshopps I had before. Are there ways to quiet it down, or would I be stuck listening to it all the time?

Also, when you say a surge, do you mean like electrical surge? That's the only sort I know of.

Sorry to be so ignorant sounding. I've had tanks before, but I've never really done the whole sump thing properly, so I'm still completely lost on it.

 

[Vinny Kreyling]

Riona, The only stupid question is the one not asked.
The surge I mentioned was water ebbing & flowing if incoming water is marginal.
A sump is a holding tank for place to put a skimmer or reactor or other stuff so it is out of site, that's about it.
The overflow box lets water back to the holding bin the pump pushes it back into the tank.
About as basic as I can tell it.
There are ways to quiet an overflow depending on a few things & each can be different. Don't let it scare you.
THE MOST IMPORTANT THIND IS: flow through the overflow u tube has to be quick enough to pull any air bubbles completely out of the tube.
Not doing so will result in an air bubble forming @ the top of the tube & eventually you loose siphon & have a flood.

 

[Riona]

@Vinny Kreyling In my case, getting my macro out of my display tank because it keeps blowing everywhere, and possibly tossing the urchin in when he gets big enough to start mowing desirable things down.

Thank you for explaining it to me like I'm dumb without actually implying that I am. I appreciate it!

That makes sense about the bubbles. If I got a box which claims to move 200 GPH, and got a return pump that'd give me about 100 GPH through the bottom tank, do you suppose that'd be enough?

 

[Vinny Kreyling]

You have to look @ what is called the HEAD CHART for the particular pump you want to use & see if there is enough flow.
Basically the pump has to push water up, against gravity & any pipe fittings like a right angle turn.
All these things are called head pressure and there should be a chart for the pump.
A DC pump can have a variable speed, an AC pump can not, BUT you can use a valve to adjust the flow without harming the pump.