Aquabacs' Cadlights Artisan 50 Azooxanthellae Tank build

[slapshot]

Mike, There is a flaw in your fridge system. I just replumbed mine directly into my return line. I think this will be more natural and allow me to add food easier as it is in the basement now rather than the closet. It exposed a weakness to me and I see you have the same.

If your paristallic pump hose ruptures, or should I say when it does, your going to be pumping water out of your system. I say when because I deal with pools in my business. We use those to feed chemicals into the pools. They always rupture eventually. To prevent this from creating a disaster you need a check valve at the points your 1/2 line enters and exits your main line. If you use a 1/2 check valve I don't think the food will clog it up.

 

[Matt_Wandell]

Another option is to just create a side stream with a venturi injector. Place a gate valve on the supply line between both ends of the bypass and use this to control the rate of flow through the bypass. The pressure on the peri pump lines should be barely negative if dialed in right, so it shouldn't rupture. Even if the peri pump line does leak somehow, you would just be sucking in air and not blowing out water.

I'd be interested to see how Steve W's system has been holding up for him.

 

[Matt_Wandell]

Oh, just looked at this diagram again. It will not really work in the current setup. The loop with the peri pumps is a dead end of sorts. You need a valve (preferably gate valve) on the section of the return line where it says "3/4 pipe". When you dial down this valve a bit you'll create higher pressure on the lower portion of the pipe than the higher part--this is what you need to get a venturi to work, or to push water through the loop. I'd recomend feeding the peri pumps into a venturi if you are concerned about the issue slapshot brings up.

 

[uhuru]

Thanks for the feedback. Matt - I sent you a PM but its probably good to answer it here so if anyone else wants to replicate it they know what to do. I think I understand your solution for forcing the flow to go through the loop by using a gate valve. Would this negate the need for check valves which slapshot recommended then?

Also, you lost me on the part about feeding the pumps into a venturi.

 

[uhuru]

Mike, There is a flaw in your fridge system. I just replumbed mine directly into my return line. I think this will be more natural and allow me to add food easier as it is in the basement now rather than the closet. It exposed a weakness to me and I see you have the same.

If your paristallic pump hose ruptures, or should I say when it does, your going to be pumping water out of your system. I say when because I deal with pools in my business. We use those to feed chemicals into the pools. They always rupture eventually. To prevent this from creating a disaster you need a check valve at the points your 1/2 line enters and exits your main line. If you use a 1/2 check valve I don't think the food will clog it up.

If the hose ruptures, how do check valves at the 1/2 pipe prevent water from being pumped out of the system?

 

[Matt_Wandell]

Thanks for the feedback. Matt - I sent you a PM but its probably good to answer it here so if anyone else wants to replicate it they know what to do. I think I understand your solution for forcing the flow to go through the loop by using a gate valve. Would this negate the need for check valves which slapshot recommended then?

Also, you lost me on the part about feeding the pumps into a venturi.

Oops! Already replied to the PM, but here's what I said:

Hi Matt,

Can you explain to me what you mean by feeding the peri pumps into a venturi?

Also, if I understand your post correctly, I can force the flow to go in one direction by creating higher pressure at the entry point vs. the exit point of the 1/2" pipe going into the fridge. This would negate the need for check valves, which I prefer to avoid since they are going to be prone to failure with all the food that goes through them. Is this correct?

Yes and yes.

Something like this 1/2" version would work.
http://www.aquaticeco.com/subcategor...tors/venturi/0

Have you used a venturi skimmer before? You just put one of these on the end of a pump and it draws air into the little nipple to make bubbles. The rate at which air is drawn into the nipple is a function of the water velocity through the pipe. In your case you control how fast the water pushes through by tuning the gate valve, but instead of sucking air you are sucking food. You don't need a whole lot of suction since the peristaltic pumps are doing the work of delivering the food to the pipe, so just tune it until you see it starting to have a bit of negative pressure.

Hope this makes sense.

 

[Matt_Wandell]

Oops again, here is the working link to the venturi:
http://www.aquaticeco.com/subcategories/3536/Turbo-Venturi-Injectors/venturi/0

This is one of a few dozen different venturi brands, all of them would work fine. You could even build one yourself.

 

[Matt_Wandell]

Here's a GIF that might make more sense too...
http://www.morgancountyseeds.com/images/inject_1_.gif

 

[uhuru]

Can you tell me where the venturi valve would be placed exactly? On the suction end of the return pump or plumbed into the 1/2" pipe?

 

[Matt_Wandell]

On the 1/2" pipe. In your diagram, right above the 3 food jars.

The 3 peri pumps complicates things just a little, but not much. Just tee all 3 together into one line that goes into the venturi suction nipple.

 

[flying_dutchman]

Just tee all 3 together into one line that goes into the venturi suction nipple.

Why not just use three venturi's lined up?

 

[uhuru]

Ok I think I get it now. I thought that a venturi had to be placed on the suction side of the pump but I guess that is only with needlewheel skimmers. So if I understand correctly the venturi by nature "sucks in" either air or water from the nipple. If I connect the peri pumps to the venturi, normally the venturi will suck in some food. If the pump tubing ruptures, the venturi will suck in air.

If this is how it works then I think 3 venturis would be overkill. It would take up space where space is limited, and unless you make your own it is a lot more expensive.

 

[Matt_Wandell]

Why not just use three venturi's lined up?

No reason, just seems overly complex to me. I guess my question would be what's the benefit?

He wouldn't be able to line the venturis up end to end (in series), if that's what you mean. He'd need to split the 1/2" line 3 ways and place the venturis side by side (in parallel).

 

[Matt_Wandell]

Ok I think I get it now. I thought that a venturi had to be placed on the suction side of the pump but I guess that is only with needlewheel skimmers. So if I understand correctly the venturi by nature "sucks in" either air or water from the nipple. If I connect the peri pumps to the venturi, normally the venturi will suck in some food. If the pump tubing ruptures, the venturi will suck in air.

If this is how it works then I think 3 venturis would be overkill. It would take up space where space is limited, and unless you make your own it is a lot more expensive.

You got it!

 

[slapshot]

If the hose ruptures, how do check valves at the 1/2 pipe prevent water from being pumped out of the system?

Hmmm I guess your right. You really need a check valve at every parri pump. You are trying to stop back flow if the tube ruptures. The way you have it now, the tube is holding the pressure keeping the water in your loop. Does that make sense?

 

[uhuru]

Yes it does. I just got back from Phishy's, picked up a 1/2" venturi. Also got a 3/4" gate valve. I think the setup Matt proposed is best for preventing water from pumping out of a ruptured peri pump tube. Not only will it function as a failsafe in case of rupture, it will reduce pressure on the tubing itself. The key is going to be getting enough flow through the 1/2" pipe for the venturi suction to work. With a 1500 gph pump I should be ok though. Hopefully I can get this up by the end of this weekend.

 

[GreshamH]

Oh, just looked at this diagram again. It will not really work in the current setup. The loop with the peri pumps is a dead end of sorts. You need a valve (preferably gate valve) on the section of the return line where it says "3/4 pipe". When you dial down this valve a bit you'll create higher pressure on the lower portion of the pipe than the higher part--this is what you need to get a venturi to work, or to push water through the loop. I'd recomend feeding the peri pumps into a venturi if you are concerned about the issue slapshot brings up.

Thanks for +1 my recommendation of using a gate valve

Awesome tips Matt I didn't think of going the venturi route.

we'll have to poke Steve and see what's up with him

 

[Matt_Wandell]

If your paristallic pump hose ruptures, or should I say when it does, your going to be pumping water out of your system. I say when because I deal with pools in my business. We use those to feed chemicals into the pools. They always rupture eventually. To prevent this from creating a disaster you need a check valve at the points your 1/2 line enters and exits your main line. If you use a 1/2 check valve I don't think the food will clog it up.

Hi, can you give us a little more info on the setup you use on pools? I assume you are pumping chlorine through the lines? Where exactly does it rupture? On the output side of the pump, or where the rotating drums contact the flexible hose? Are you pumping it into a pipe like with this feeding setup, and if so, do you know the pressure in psi inside that pipe? What brand and model of peri pump are you using?

Thanks,
Matt

 

[slapshot]

Hi, can you give us a little more info on the setup you use on pools? I assume you are pumping chlorine through the lines? Where exactly does it rupture? On the output side of the pump, or where the rotating drums contact the flexible hose? Are you pumping it into a pipe like with this feeding setup, and if so, do you know the pressure in psi inside that pipe? What brand and model of peri pump are you using?

Thanks,
Matt

We do indeed use them to pump chlorine and acid into the return pipes of the filters. I am not sure there is any rime or reason for them to break they just do. Mostly inside the pump probably from the wheel. I have replaced one that ruptured in my dosing system for my tank. The pools all have check valves at the point of entry to the main pipe. I have done the same with my feeder. I also think they don't pump consistently if they are under pressure, especially as they age

 

[Matt_Wandell]

We do indeed use them to pump chlorine and acid into the return pipes of the filters. I am not sure there is any rime or reason for them to break they just do. Mostly inside the pump probably from the wheel. I have replaced one that ruptured in my dosing system for my tank. The pools all have check valves at the point of entry to the main pipe. I have done the same with my feeder. I also think they don't pump consistently if they are under pressure, especially as they age

Thanks, that makes sense. I assume that chlorine and acids would eat away at the material faster.

I've heard of people having their hoses leak but to be honest have never had it occur before and I wonder what the difference is--materials, fluid moved, pressures? FWIW I've had a LM3 in continuous operation since about 2002 or so, and several cheap OEM pumps in use for the last 3 years, all without ever needing to change out the tubing that contacts the rotating parts. They are all pumping into air (zero pressure), so perhaps this is the difference.

I will be setting up a system like uhuru and Mike have in the future (5g auto feeder going into 1/2" pipe) and intend on using a venturi just to be on the safe side.