Wave and added stress

dawgface

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How many of you keep a constant wave in your tank and do you worry about the integrity of the tank due to the added stress?
 
As you know, I don't have years of experience but unless you are talking a tsunami I would be surprised if it would affect the integrity of the tank at all.
 
From what I have read, adding a constant wave potentially decreases the tank's "expected life(around 20years)" down by 5-10 years.
 
I would think age of tank type of seal ,glass , acrylic, size ,eurobraced, rimless, trim size of wave would all play into this and if it did happen how would you know for sure thats what caused it
 
I have mine programmed to nutrient export/wave for only 15 minutes a day due to that fear. Surely it will hasten a failure. It would be like a house under a constant 3.5 earthquake. Not a big deal once a year but several hours a day year in and year out- bad news.
 
When the Vortech's first came out I had this same question to EcoTech and it was a massive topic on RC. The conseusus was that the stand was more of a concern than the tank.
 
DawgFace;750868 wrote: How many of you keep a constant wave in your tank and do you worry about the integrity of the tank due to the added stress?
How would a wave cresting at the top of the tank add anymore stress than tank filled to the same height with a powerhead blowing 3600gph constant on the same panel?
 
JeF4y;750928 wrote: When the Vortech's first came out I had this same question to EcoTech and it was a massive topic on RC. The conseusus was that the stand was more of a concern than the tank.


This topic is specifically addressed in the MP40wES Owner's manual as well. I think EcoTech states you do it at your own risk, and they have no liability if your tank fails when using a wave pattern, hehehe!
 
grouper therapy;750931 wrote: How would a wave cresting at the top of the tank add anymore stress than tank filled to the same height with a powerhead blowing 3600gph constant on the same panel?

It's not the flow of the water, it is the constant uneven weight distribution.

I would assume that if you manually rocked the tank and stand back and forth, that it would increase a chance of failure as well.
 
Ripped Tide;750944 wrote: It's not the flow of the water, it is the constant uneven weight distribution.

I would assume that if you manually rocked the tank and stand back and forth, that it would increase a chance of failure as well.
That is a different scenario. You are actually moving the tank and stand at that point. I understand the uneven weight distribution but at it's peak how is the pressure more than at full tank .? The water pressure is the same since the depth is the same. I would see it if the tank was half full and the wave was slapping the end of the tank at a high rate but a 2" wave that barely peaks higher than the tank at rest.

Edit: Take a salt bucket and fill it to within a couple inches of the top, put the lid on and shake it sideways. Now pour out the water until it is just over half full replace the lid and shake sideways. Compare the two
 
grouper therapy;750968 wrote: That is a different scenario. You are actually moving the tank and stand at that point. I understand the uneven weight distribution but at it's peak how is the pressure more than at full tank .? The water pressure is the same since the depth is the same. I would see it if the tank was half full and the wave was slapping the end of the tank at a high rate but a 2" wave that barely peaks higher than the tank at rest.

In a 450 gallon tank, 2" of water weights like 500lbs. On a large scale, it can be even more.

Imagine sloshing 400lbs back in forth in a tank.



You should come see what. 1" wave on my little 93 cube does.
 
Ripped Tide;750970 wrote: In a 450 gallon tank, 2" of water weights like 500lbs. On a large scale, it can be even more.

Imagine sloshing 400lbs back in forth in a tank.



You should come see what. 1" wave on my little 93 cube does.
First of all 2" of weight will vary depending on the dimensions of the tank. So 400lbs is not a constant and irrelevant. Hypothetically if it was 400 lbs the entire 400lbs is not forced against the tank all at once. I will agree that there is inertia that is applied but the question would be how much over how big of an area for how long and is it enough to stress what the tank is designed for. In all actuality you and I probably don't have sufficient data to prove the theory either way.:tongue::D

Edit: Let me ask this . If the wave never reached the surface would it have the same effect?
 
grouper therapy;750979 wrote: First of all 2" of weight will vary depending on the dimensions of the tank. So 400lbs is not a constant and irrelevant. Hypothetically if it was 400 lbs the entire 400lbs is not forced against the tank all at once. I will agree that there is inertia that is applied but the question would be how much over how big of an area for how long and is it enough to stress what the tank is designed for. In all actuality you and I probably don't have sufficient data to prove the theory either way.:tongue::D

Edit: Let me ask this . If the wave never reached the surface would it have the same effect?

The weight of the water distributed over the bottom of the tank is a direct relation to the height of the water. But that will be minimal if it changes only by 2". The inertial force would be the bigger concern in my opinion but again, I think it would be minimal. Do I have scientific data to back that up no. Just my opinion. As for the disclaimer in the product manual, I am sure that is the result of someone trying to blame a tank failure on wave action. For the manufacturer it is easier to put a disclaimer in than to fight each time someone blames them.
 
Maelstrom79;751000 wrote: Anyone have a degree in physics ? ;)

I have every confidence that Robb and Stacy could tackle this one........

Edit: I'm humming the JEOPARDY theme now..........
 
This is interesting and I'm about to cover waves in my Physics class next week according to my physics syllabus. I'll have to talk to my Professor about it when we cover it.
 
you know, someone could just put their tank on a constant standing wave for awhile and we should find out soon enough, maybe two mp60's on a 55 gallon 3/4 full.
Still, I doubt that it would ever be an issue. I would imagine you are more likely to make your tank fail by scraping off your silicone while cleaning the glass of your tank
 
"A pessimist in an optimist that knows all of facts." :-) I am also a worst-case thinker, so don't go by me.
 
Anybody see any of the video footage of that little Tsunami over in Japan. Moving water definitely has some force to it.

Not an engineer, but when you add energy to the water, you are no longer just talking about the weight of just the water being the only force.

Did a little research and found this http://www.americansealantsinc.com/wp-content/files_mf/techdata_asi_aquariumsealant.pdf">http://www.americansealantsinc.com/wp-content/files_mf/techdata_asi_aquariumsealant.pdf</a> I doubt this covers all aquarium silicones, but given their location relative to Marineland (Perfecto) and all glass I would imgine these guys are the suppliers. I was suprised to see the tensile strength and the shear strenth were so different. However that would be consistent with some other reading I did that basically said the most likely failure point would be the seam with the bottom glass. As tensile would be the direct pulling of the joint of the front glass to the sides and lap shear would be the sides of the tank pulling away from the bottom.

Makes me want to rethink putting that Vortech on the back glass in addition to the two on the side. Kind of explains why frames and euro bracing add so much strength.
 
Water sloshing back and forth, exerting periodic stress well in excess of the pressure of standing water (constant flow from a powerhead is irrelevant), will most definitely weaken your seals much faster than it would otherwise. I haven't tried it, but I'll pretty well guarantee it. I know from my work in the oil & gas industry that with the volumes of liquid pumped into and out of said tanks at high rates that this is a concern in the design and engineering of the tank both as regards its external structure but its internal geometry.
 
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