Is there an ACTUAL fix for the Red Sea downflow valve?

[stevolough]

I do have two Red Sea ReefWave wavemakers, and they're set on reef mode, which is random. But that shouldn't affect the water level, right? They just move the water that's in the display tank.

If I put my wave makers facing the overflow on random mode I do have issues. Instead of a gravity overflow I’m pushing water into it.

 

[TheBear78]

My 425 only needs adjusting once in a while. Is it possible your return pump isn’t holding steady flow?

Me too. I tweaked mine this week but haven't had to touch it in about 3 months. I set my water level at the edge of the emergency drain and the only noise I've had is the trickle into the socks. Some floss on top silences this nicely.

For info, I have a TMC Reef Pump DC 4000 running at full speed which is around 7 1/2 x turnover.

 

[NigeltheBold]

So, from what I'm hearing/reading here and elsewhere, some Reefer owners have this problem and others don't. Some people just let the water level rise up to the emergency overflow and they just live with a small amount of water trickling into it constantly. Others have found a way to let the water level go down in the overflow box, but prevent air from being sucked into the main overflow pipe. Neither of these are actual fixes, unfortunately.

I think I'll try buying a new return pump to see if that helps. The only other thing I could potentially change would be the wavemakers, but I spent a lot of money on those and I obviously want my tank to have enough water movement.

Since starting this thread a few days ago, my water level in the overflow has slowly risen back up to the lip of the emergency overflow and is now trickling down. It's not making noise, but it's not supposed to be doing that. Plus, any water that goes into the emergency overflow pipe is being missed by my roller mat filter.

Not sure what else to do. When I contacted Red Sea about the problem, they said something along the lines of "it's normal to have to adjust the downflow every now and then" which obviously doesn't help my situation. If anyone finds an actual solution, please let me know!

 

[TheBear78]

To be honest I never expected to be able to maintain a perfect balance where the water level just stayed in one spot. I would even consider it unrealistic but I appreciate that people do manage it.
I do have my water level at the rim of the emergency overflow and it's quite likely that a few drops go over, especially as the wave maker pulses and pushes waves into the overflow box. However, it makes no noise in this position so I don't feel the need to fiddle.

 

[NigeltheBold]

If you think about this from a logical standpoint, it should be pretty difficult to get the water level to stay in the same spot. Here's my reasoning:

Let's say you have a return pump that pumps 1000gph. And let's say you start with the downflow valve all the way open. In this position, the water flowing into the overflow box and down the return pipe is flowing at a higher rate (faster) than the return pump is pumping. Let's say it's flowing down into the sump at 1025gph (could be higher, there's no way to know, but the point is, it's more than the pump) and the pump is still pumping at 1000gph. So the water level in the overflow box is the lowest that it'll go, and it's sucking air into the downflow pipe.

So you start to close the downflow valve to try and balance the flow rates. Let's say that after you turn the valve handle about 1/2 turn total, the water level starts slowly creeping up in the overflow box. The overflow pipe stops sucking in air. Why? Because the water flowing down the overflow pipe is now flowing at a lower rate than the return pump is pumping, due to the valve being a bit more closed than before. So now, the pump is still pumping at 1000gph but water is flowing down into the sump at 975gph (again, arbitrary numbers, but I'm trying to prove a point).

At this point, the water level shouldn't just magically "stop" creeping upward. You've found the spot on the downflow valve that brings the water level up (i.e. the flow rate into the tank is higher than the flow rate out of the tank). The flow rate back into the sump won't automatically adjust itself from 975gph to 1000gph to match the pump. In order to get the water level to stop moving upward, you have to dial-back the downflow valve before the water level reaches the emergency overflow. If it reaches the emergency overflow, you basically have to start over because you need to lower the water level before you stop it in the ideal position (unless you can somehow stop it right at the top of the emergency pipe without getting a drop of water down the pipe- which would be pretty hard to tell)

So, how do you know how much to dial-back the downflow valve? You don't. You only know that it's less than 1/2 turn. You started with too much downflow, now you have too little. You have to find the correct spot somewhere in between (in this example it would theoretically be the exact middle, but that would never actually be the case). And this is where the problem lies, at least for some of us. If you can't match the pump flow exactly, the water level will slowly move up or down in the overflow box until it reaches the emergency overflow pipe or it bottoms-out and the downflow pipe starts sucking in air. Apparently some people are able to find the perfect valve position, but I've now heard from multiple people who can't, no matter how hard they try (I'm one of those people). Even when making the tiniest adjustments to the downflow valve (barely feeling any handle movement), the water level either creeps upwards or downwards and never stays in one spot. And that actually makes sense if you think about it... what are the odds that you have the valve set to exactly match your pump speed? And when I say "exact," I mean dead-on, otherwise the level will rise or fall. Seems like it would be pretty tough to do that, but apparently some people have done it.

If the return pump speed is somehow fluctuating, that will cause issues. If your downflow rate somehow fluctuates (maybe due to a blocked pipe or buildup at the downflow valve), that will cause issues.

Am I missing anything? Does my logic make sense?

 

[TheBear78]

Your logic makes sense to me.
Have you seen this thread before? Post #8 is quite insightful.

 

[TheBear78]

Double post...

 

[KrisReef]

I have a Reefer 525xl and I've already replaced the stock diaphragm valve with a gate valve. It helped a little, but I'm still constantly adjusting it to try and keep the water level about an inch or so below the mouth of the emergency overflow pipe. Personally, I don't think the valve was the issue. I think the design of the overflow is the issue. In order to maintain the water level in the tank's overflow box, you have to match your pump's flow rate exactly. If the valve is a tiny bit too far open, the water level will drop and eventually you'll start hearing air going through the overflow. If the valve is a tiny bit too far closed, the water level will rise and eventually start going down the emergency overflow (which isn't ideal, especially if you have a roller mat filter in your sump that's only hooked up to the main overflow tube). A gate valve doesn't change that... you still have to bring the water level to the correct position, then find the sweet spot in the valve in order to match the flow rate. And even if you do seem to magically hit the spot, several days later, you have to start all over (at least, that's what happens with mine).

So, is there an actual fix that will eliminate the need to adjust the downflow valve? Because the gate valve isn't doing that.

I found this product being sold on eBay. I don't know if this will prevent water going into the overflow pipe though... It may just reduce the noise.

I've had my tank for a couple of years now, and I figured someone would've come up with a permanent fix by now. But unfortunately I'm not finding anything.

Not specifically familiar with your particular equipment and situation but getting pumps and return flows remaining stable over time and keeping overflows quiet can be an unsolvable puzzle with variable speed pumps, growing algae that slowly obstructs flow, and waves, evaporation, and all the other sources of change that can upset the delicate balance in our systems.
My experience with calcium reactor balance caused me to buy a metered flow pump, a metered bubble regulator and with all the control I purchased The random impacts of co2 accumulation and tube obstructions have guaranteed that there will be some issue every 6 months or so that requires fiddling around to keep it working properly. My tank overflow is similar and the only solution is to remain vigilant or tear down the setup to remove the agitation.
Anybody who tells you otherwise is a great big liar destined for eternal dam nation imo.

My apologies for the harsh situation but knowledge is your best friend for figuring out how to make do and decide how best to move forward.
I hope you do find a good solution better than my suggested outcome
!

 

[ScubaFish802]

You could also blame the return pumps for fluctuating output as well as the filters for getting clogged up, etc..
I don't think it is possible to really set it and forget it forever - I re-adjust mine after weekly water changes usually

 

[Cartoonfanboy]

@NigeltheBold did you resolve this? I have exactly the same issue where over time normally 24 hours the overflow level increases and then my ATO kicks in and I end up using more and more ATO water.

 

[Sabellafella]

To be honest guys I have my valve set to surface skim the water on the emergency. Every 3 - 4 weeks I'll completely open it to clear it out. Works great for years and years now.

 

[NigeltheBold]

@NigeltheBold did you resolve this? I have exactly the same issue where over time normally 24 hours the overflow level increases and then my ATO kicks in and I end up using more and more ATO water.

Not really, no. I bought a new pump hoping it would help. It may have helped a little, but the problem still exists. I find the sweet spot, and then a couple days later, I have to start the process over.

 

[NigeltheBold]

To be honest guys I have my valve set to surface skim the water on the emergency. Every 3 - 4 weeks I'll completely open it to clear it out. Works great for years and years now.

Glad that works for you, but it's not the way it's supposed to work. Those of us who have a roller mat filter hooked up to the main downflow drain don't want any water going into the emergency overflow because it gets skipped by the filter.

 

[Sabellafella]

Glad that works for you, but it's not the way it's supposed to work. Those of us who have a roller mat filter hooked up to the main downflow drain don't want any water going into the emergency overflow because it gets skipped by the filter.

Ahh I see.

I've had my reefer since 2015. I've tried at one point to keep the water level stable before the emergency and long term just never worked out for me. No matter what I have to bleed the valve every 3 or so weeks. It never stays put in the overflow, chalked it up to just how the diaphragm valve is made. Main drain design pulls water from the bottom of the overflow, giving you a higher chance of putting heavier particulates into their diaphragm valve.


Definitely have a better chance at what you guys are trying to achieve using the gate valve over red sea.

 

[NigeltheBold]

Ahh I see.

I've had my reefer since 2015. I've tried at one point to keep the water level stable before the emergency and long term just never worked out for me. No matter what I have to bleed the valve every 3 or so weeks. It never stays put in the overflow, chalked it up to just how the diaphragm valve is made. Main drain design pulls water from the bottom of the overflow, giving you a higher chance of putting heavier particulates into their diaphragm valve.


Definitely have a better chance at what you guys are trying to achieve using the gate valve over red sea.

Yes, the gate valve helps, but doesn't solve the problem. You have to match the downflow speed to the return pump speed exactly, otherwise the water level will drift up or down in the overflow box. I have no idea how so many people have managed to match the pump speed exactly... I've now tried it with multiple pumps, and the longest I've had a stable water level in the overflow box is about 3 days.

 

[HankstankXXL750]

I have 5 Red Sea tanks 350, 525, 750, 900, 1000. I run e-flux dc pumps. Started the first two in May of 2021. Once I get them set I hardly ever have to adjust anything. My auto top off isn’t working properly in my 350 so my wife will open the valve when it starts blowing air and I will have to correct the issue and then re adjust the valve. I close it to a point where the water starts to raise I watch and close until it gets really close to the emergency. There is some forgiveness as the overflow will run quietly between the lowest quiet level and actually overflowing in the emergency pipe. However it takes a certain amount of time to equalize. Once I get it close I check it every 5 minutes or so to see if it is stable. I haven’t had to touch them hardly ever.

That being said I do have a vermetid snail issue. I think that there are times that they grow in the pipes and at times I try to eliminate them. Aside from external things like this, mine stay perfect. Maybe I’m lucky, I think I find it easier to start with too little flow and open it slowly.

 

[FSP]

Not a valve issue, just the nature of Herbie overflows with a true dry emergency line. They're finicky.

If it really bothers you, I'd move the return from the overflow box and plumb it over the top. Black PVC helps. Then use the hole for a three drain setup and never worry about it again

 

[Midrats]

^^^This^^^

 

[gbrowerjr]

I know this is old but how many gph is this pump? With red sea's horribly sized plumbing return pumps are heavily restricted. I lose 90 percent of my flow according to my flow sensor on several different pumps. My theory is that return flow is so low that the down pipe flow has to be so closed down that it doesn't take much biofilm/detritus/etc to further restrict the overflow causing the overflow level to rise. Sometimes it will "flush" itself and with all the adjustments that have been made as it restricts the valve is way to open causing air bubbles in the down flow. I have found that periodically opening the valve several turns flushes the system and lengthens the time between adjustments. Regular cleaning of your return pump and the valve also helps. I really do wish red sea would implement a 3 down pipe over flow with full, partial and emergency. It is a much superior and less finicky system.

 

[NigeltheBold]

I know this is old but how many gph is this pump? With red sea's horribly sized plumbing return pumps are heavily restricted. I lose 90 percent of my flow according to my flow sensor on several different pumps. My theory is that return flow is so low that the down pipe flow has to be so closed down that it doesn't take much biofilm/detritus/etc to further restrict the overflow causing the overflow level to rise. Sometimes it will "flush" itself and with all the adjustments that have been made as it restricts the valve is way to open causing air bubbles in the down flow. I have found that periodically opening the valve several turns flushes the system and lengthens the time between adjustments. Regular cleaning of your return pump and the valve also helps. I really do wish red sea would implement a 3 down pipe over flow with full, partial and emergency. It is a much superior and less finicky system.

I think my pump is supposed to put out 1900gph. I've never measured the actual flow though.

I've beaten my 3-day record and gone 5 or 6 days without having to adjust the downflow knob. But the water level moves slowly up or down and never stays exactly in the same spot. Not sure what's impacting it the most... detritus in the downflow tube, wavemakers, the rotation of the earth, maybe gremlins? I don't know.

The tank is healthy and it's a somewhat minor inconvenience at most... I don't think I want to try anything drastic to attempt to fix it. In future tanks, I'll probably go with a 3-pipe downflow setup.