First Time Using Flex PVC - new 220

Rjramos · Mar 25, 2019

From my experience, here is how I see it. The flex PVC works fine in most applications, where I have had problems is between flex PVC and a bulkhead, there I’ve had leaks. I’ve always worked with Durso drains, but I’ve made them myself with a T and a cap with the air vent on it, instead of a elbow like you have. I don’t have the hole on the side like yours and the marineland dursos. Overall, as mentioned, pump is putting out more than dursos can handle. A dursos vent should not be submerged in water within the pipe, otherwise, instead of drawing air and maintaining steady water level, it will seesaw up and down. The air intake should also be either adjustable with a valve or drilled to the right size according to how much water is draining out. The more water drains,the smaller the air vent has to be to maintain proper water level in the overflow box so start small and work up.Down below, remember water whether pumped or gravity fed is gonna seek the path of least resistance. I would say by the picture, that the drain coming from the left overflow is faster than the one from the right. This could be corrected by either using 45 elbows on the right drain, or as I have done, bring both drains to a manifold and from there, 2 pipes to your sump. As far as your returns from the pump, same thing applies, the right return is getting more water. One way to correct is to place 2 gates on each return line rather than 1 right after the pump. I like your idea of teeing off the return into a Refugium to reduce the display turnover. I have set up this way but I place the refugium over the main sump and use drain water from the tank rather than return from the pump. The refugium basically drains to the sump below it. I have fed an external protein skimmer and display return from a powerful pump, reducing skimmer line to3/4” and gating down. My last observation and question. The sump level looks kind of high. Can it handle the main displays residual water return in a power outage until the return nozzles break syphon below the water?

Here are some pics of a currently running 120 gal with refugium on a shelf above main sump. The manifold was made with 1 1/4” pvc. The line with gated valve to the right feeds the refugium, the one with gated valve to left feeds straight to the bottom sump. A Blueline 70 on this set up is feeding an MRC M1 skimmer and returning water to main display. Tanks been running solid since 2006.

ZsWithTheFishes · Mar 25, 2019

Rjramos said:
From my experience, here is how I see it. The flex PVC works fine in most applications, where I have had problems is between flex PVC and a bulkhead, there I’ve had leaks. I’ve always worked with Durso drains, but I’ve made them myself with a T and a cap with the air vent on it, instead of a elbow like you have. I don’t have the hole on the side like yours and the marineland dursos. Overall, as mentioned, pump is putting out more than dursos can handle. A dursos vent should not be submerged in water within the pipe, otherwise, instead of drawing air and maintaining steady water level, it will seesaw up and down. The air intake should also be either adjustable with a valve or drilled to the right size according to how much water is draining out. The more water drains,the smaller the air vent has to be to maintain proper water level in the overflow box so start small and work up.Down below, remember water whether pumped or gravity fed is gonna seek the path of least resistance. I would say by the picture, that the drain coming from the left overflow is faster than the one from the right. This could be corrected by either using 45 elbows on the right drain, or as I have done, bring both drains to a manifold and from there, 2 pipes to your sump. As far as your returns from the pump, same thing applies, the right return is getting more water. One way to correct is to place 2 gates on each return line rather than 1 right after the pump. I like your idea of teeing off the return into a Refugium to reduce the display turnover. I have set up this way but I place the refugium over the main sump and use drain water from the tank rather than return from the pump. The refugium basically drains to the sump below it. I have fed an external protein skimmer and display return from a powerful pump, reducing skimmer line to3/4” and gating down. My last observation and question. The sump level looks kind of high. Can it handle the main displays residual water return in a power outage until the return nozzles break syphon below the water?

Here are some pics of a currently running 120 gal with refugium on a shelf above main sump. The manifold was made with 1 1/4” pvc. The line with gated valve to the right feeds the refugium, the one with gated valve to left feeds straight to the bottom sump. A Blueline 70 on this set up is feeding an MRC M1 skimmer and returning water to main display. Tanks been running solid since 2006.

Thank you for your reply and feedback - great information!

I suspected that there may be problems in the bulkhead fittings with the flex PVC and so everything coming out of the bulkhead is rigid and is converted to flex 4+ inches down. The flex PVC could not be inserted as far into fittings, and I figured combining that with the rounded edges of the interior bulkhead would be a disaster waiting to happen.

Good point about the different flow rates, I'm almost positive that the right is draining more. I do have adjustable valves going into each input on the sump, I may tighten the right hand side and see if I can get the flow more even. That may be what was causing the durso on the right to drain out of the hole in the side.

I'm still debating on having the separate refugium being fed from the main display or from the return. One of the reasons that I chose the return initially was because that refugium is intended to be a display, and I did not want particulates from the main display to end up in the refugium. It does seem is the water directly from the main display might contain more nutrients for macroalgae coming from the return, however. I still haven't made my mind up on that, it will take more research.

I have tested the sump and it can handle the backflow when the pump is powered down. What I don't know is how well the overflows are connected to the main tank... A small leak there could put a bit more water into the sump. But there's a drain to the outside in those situations (we don't have many power failures where I live). Regardless, the sump has at least a couple inches of space.

_Alex_ · Mar 26, 2019

I would slow the pump down then remove a bit of water once stabilized to lower the level in the sump back down to what it was at higher speed.

Then once you t off for a refuge you can up the flow again if you choose. I guess if the pump can handle being dialed back. I can’t remember what your using and I didn’t look [emoji102]

ZsWithTheFishes · Mar 29, 2019

Rjramos said:
I would say by the picture, that the drain coming from the left overflow is faster than the one from the right. This could be corrected by either using 45 elbows on the right drain, or as I have done, bring both drains to a manifold and from there, 2 pipes to your sump. As far as your returns from the pump, same thing applies, the right return is getting more water. One way to correct is to place 2 gates on each return line rather than 1 right after the pump. I like your idea of teeing off the return into a Refugium to reduce the display turnover. I have set up this way but I place the refugium over the main sump and use drain water from the tank rather than return from the pump. The refugium basically drains to the sump below it. I have fed an external protein skimmer and display return from a powerful pump, reducing skimmer line to3/4” and gating down. My last observation and question. The sump level looks kind of high. Can it handle the main displays residual water return in a power outage until the return nozzles break syphon below the water?

I played around with the valves going into the sump, and it looks like it was actually the right one that was draining fast (there are elbows on the left which were not pictured). I tuned down the right side drain and it fixed the issue with water getting sucked into the side hole of the durso on the right. Now the tube on top allows it to be adjustable like the left and I was able to really quiet things down.

_Alex_ said:
I would slow the pump down then remove a bit of water once stabilized to lower the level in the sump back down to what it was at higher speed.

Then once you t off for a refuge you can up the flow again if you choose. I guess if the pump can handle being dialed back. I can’t remember what your using and I didn’t look [emoji102]

Skimz L90. I was feeling a little bit of sticker shock after buying my lighting / sump / salt etc and the price was right on the pump.

I salted it up yesterday and the loud bubbling is gone, it is now foaming at the top of the sock instead. I turned the pump back up to full throttle, and though it isn't dead silent it is one of the quieter tanks in my house now

I'm going to add some rocks and start cycling it today. I should also have some gear coming in the mail

ZsWithTheFishes · Mar 29, 2019

Gear day! Added the gyre 330 to the left side and 20 lb of life or up to the sump. That powerhead puts out some juice... All that surface agitation and it's only at 50%. I can't hear it at 100% over the other tanks.