Tank/Sump Setup

[theotheragentm]

My friend and I were originally going to build a tank (acrylic), set up and overflow to a sump, where the water would be pumped back to the tank. Drilling would have been pretty simple, but we came across a great deal on Craigslist for a glass tank and stand.

So now we have a glass tank, which I am not comfortable drilling. I don't want the filter to be over the tank, so I still need to gravity drain. How can I accomplish this? Overflow box? Can I build my own?

Also, I was planning to use a few pieces of PVC to put some of the piping together on this. It's very little. Since I was planning to use silicone anyway to seal sump, can I just seal the fittings with silicon too rather than PVC cement? What type of silicone is the aquarium safe one?

Thanks for your help.

 

[goisles1]

You can buy an Overflow Box for around $100 make your own overflow Box.or make your own overflow using PVC.

I built my Sump with a PVC overflow. I found a thread on how to make these on another reef forum. It seemed to work quite well for a few weeks until I lost my Syphon 2 times in the same day. Luckly, I happened to be sitting near the tank BOTH times and was able to shutdown the pump before too much water overflowed from the main tank.

Anyway, Air is getting into the system somewhere. I will be connecting the Airline tubing to a Tom's AquaLift Pump on Friday and will start testing again. My hope is that the pump will suck out any Air that might get into the syphon. Plus, if power is lost it will make sure it get's primed if needed.

I'm starting to think I should have just bought the CPR overflow Box.

I'll look for the thread and post it if I find it.

on your other question.. Not sure if you can seal PVC with Silicone. But I think it would be much easier just to use PVC cement.

 

[Ziggy953]

I would suggest buying an overflow rather then making one. They aren't to expensive and worth every penny.

I would not use silicone to hold PVC together. It will fail eventually. Use the correct cement for PVC.

 

[jsoong]

I made my overflow ... mainly as a challenge & also so I can make it really narrow at the back. <Commercial overflow box needs 6" clearance, mine is only 2.5".>

It is very challenging to make it work properly. Depth of the overflow box & sizing of the siphon are critical, & has to be matched to the pump flow. <Too small siphon for pump ... flood, too big & it entrains air & break the siphon .... flood.> It took a lot of trial & error to get it right (and 3 prototypes.) So unless you love to experiment, go buy one pre-made .... <It is cheaper by the time you buy the material for the 2nd & 3rd try!>

Oh yes, silicone will not stick to PVC ... buy the cement for $0.99 so you can sleep at night.

 

[theotheragentm]

I assumed PVC cement is safe for the fish since it can be used on drinking systems. Is this is the case for all PVC cements? I just took the stuff from my warehouse at work. We sell all kinds of the PVC/CPVC parts.

Anyone know the answer to my question about which silicone to buy from the hardware store? I know I don't want the one with the anti-fungal property.

 

[jsoong]

I think any PVC cement will be fine once cured. To be extra safe, you can use one specific for drinking water.

It used to be that GE Silicone I is aquarium safe ... but the web site now says this also contains mildewcide (same as GE type II), so it may be out. If you are in Canada, Rona & Canadian Tire house brands 100% pure silicone are marked as aquarium safe.

 

[jim692]

I assumed PVC cement is safe for the fish since it can be used on drinking systems. Is this is the case for all PVC cements? I just took the stuff from my warehouse at work. We sell all kinds of the PVC/CPVC parts.

Yes, any PVC or CPVC pipe or cement will be fine. Don't mix PVC pipe with CPVC cement or vice versa.
I would let it fully cure for maximum joint strenth. Figure 3-4 hours @70'F for the most part.
Rinse it well to keep any junk from inside the pipe from the tank.

 

[Ziggy953]

I made my overflow ... mainly as a challenge & also so I can make it really narrow at the back. <Commercial overflow box needs 6" clearance, mine is only 2.5".>

What overflow box are you talking about? Mine are rated for 1200gph each and they are only 3" on the out of the tank portion.

Make sure that your PVC cement is cured before running SW through it.