Coast to coast weir questions

hansoloNZ · Mar 22, 2017

Hi all. I'm keen to set up a gravity fed pvc pipe coast to coast weir overflow for my new 250litre tank. (very similar to the setup in this video: ).

I have a couple of questions and any comments will be hugely helpful.

1. Will 25mm (1inch) pipe and bulkheads be sufficient if l have a 1 meter long pvc weir and 2 outlet pipes at each end? Or should l use 32mm (1.5inch) pipe and bulkheads?

2. If l drill a 45mm diameter hole in the back, 45mm from the top edge, would this be safe? The glass is 6mm thick.

Thanks so much! [emoji5]️

ReeferBob · Mar 22, 2017

That design is not good at all I would not copy almost any of it. For one he has no surface skimmer really just that slit which does do something but not enough. It also will be fairly loud constantly sucking water. If you want a coast to coast, you can build an internal weir using glass siliconed to the back and sides of the tank. You do not need "teeth" you can just have the edge of the glass. The strength of a C2C is the massive surface skimming.

Also your tank will drain back to the lowest point of the drains (the opening) in the tank. For his setup, that will drain possibly more than the sump can handle.

Typically the recommendation is 1-2 hole lengths from the edge for your drilled holes. A 1" will flow plenty either in full siphon or durso drains for that size tank and maybe up to 125 gallons.

Also I would not use the check valves regardless of their design - at least not use them as part of your flood avoidance plan.

Ted_C · Mar 22, 2017

I tried this design. If you want any appreciable flow from returns - this doesn't work. The max flow of the pvc pipe (even 1.5" pipe) was below 200 GPH. The below comment mentions 500 GPH - but you have to cut this in half as the pipe fills up.

Any more flow and your not surface skimming any more - your simply pulling water in from underneath the surface.

From the comments section of the video:

Yes, the skimmer bar is gravity fed. It is not a full siphon, but rather a drain. 1" dia PVC pipe can drain approx. 500gph. Use this area/gph conversion to calculate how much slot needs to be cut then double it so you have a decent amount of flood protection. I installed 3/4" loc-line tubing to direct the return flow as desired. Check out the part 2 video and you'll find more detailed answers to these questions. Good luck.

glagunda · Mar 22, 2017

hansoloNZ said:
Hi all. I'm keen to set up a gravity fed pvc pipe coast to coast weir overflow for my new 250litre tank. (very similar to the setup in this video: ).

I have a couple of questions and any comments will be hugely helpful.

1. Will 25mm (1inch) pipe and bulkheads be sufficient if l have a 1 meter long pvc weir and 2 outlet pipes at each end? Or should l use 32mm (1.5inch) pipe and bulkheads?

2. If l drill a 45mm diameter hole in the back, 45mm from the top edge, would this be safe? The glass is 6mm thick.

Thanks so much! [emoji5]️

Coast to coast overflow on a 75 gallon. Used 1.5 inch pvc. No complaints. Can handle a 2000+ gph pump with no problems. Skims water surface like a boss depending how you adjust it. Drilled the holes on mine 3 inch away from the edge.

hansoloNZ · Mar 22, 2017

glagunda said:
Coast to coast overflow on a 75 gallon. Used 1.5 inch pvc. No complaints. Can handle a 2000+ gph pump with no problems. Skims water surface like a boss depending how you adjust it. Drilled the holes on mine 3 inch away from the edge.

Your setup looks awesome! Do you have a slot in the top of your bar or just holes drilled? Thanks heaps.

glagunda · Mar 22, 2017

hansoloNZ said:
Your setup looks awesome! Do you have a slot in the top of your bar or just holes drilled? Thanks heaps.

Holes drilled. You can adjust to to how you need to if you want to skim the surface.

SuperDragon · Mar 24, 2017

Thats how I designed mine. External overflow with teeth almost all the way across with a Beananimal two 1" drains and one 2 inch emergency. A ghost overflow or 20" synergy reef overflow are both nice options too.

Rakie · Mar 24, 2017

That is a bad design dude. Everyone keeps telling you, but you like it anyways for some reason (i'm guessing cost).

Well it doesn't work. It doesn't skim the surface water, you can tell just by looking at it. It's sucking down water from BELOW the surface (AKA, doing nothing useful).

Get a real one. Or modify that so heavily that it looks completely different -- because what you want doesn't work.

hansoloNZ · Mar 24, 2017

Thanks for the honest opinion Rakie. I'm actually considering it for a freshwater setup. I'm fairly ocd when it comes to clean water and am keen to try a sump system. I totally understand it's not the best at surface skimming but f/w doesn't require it. ;-)

Rakie · Mar 24, 2017

hansoloNZ said:
Thanks for the honest opinion Rakie. I'm actually considering it for a freshwater setup. I'm fairly ocd when it comes to clean water and am keen to try a sump system. I totally understand it's not the best at surface skimming but f/w doesn't require it. ;-)

No problem! Since I was a kid my motto has been "beating around the bush never helped anybody" -- That's not true, but I sure embraced it like fact lol.. So personally, I have much more experience in FW than SW (Been keeping fish since I was 8) and I'd say surface skimmers are still one of the best things for a tank. The surface is where the oils and other particulate will still end up. Unless you have fine surface plants like duckweed id still say that a surface skimmer is ideal.

I used to run big cichlids. Parachromis Dovii, Motaguensis, Vieja, etc etc.

Check out monsterfishkeepers.com for more info from the hardcore FW guys. If you haven't been there before, it's intense. Look up the 50k tank with Arapaima Gigas

If you're unfamiliar with Arapaima -- MFK is where the keeper of these guys go