Does coralline algae protect Red Sea seals?

[StartingATank]

Just something I was wondering whenever I was looking at my tank (yea it is a Red Sea), if coralline algae began growing on the seams and glass near them, does it protect the seams from algae breaking down the sealant, leading to seam failure? Just a curious question.

 

[tbrown]

My understanding from one of the people that helped design the Red Sea tanks was that the front panel not being supported is the main cause of the seam failures.

 

[StartingATank]

My understanding from one of the people that helped design the Red Sea tanks was that the front panel not being supported is the main cause of the seam failures.

Ah that makes sense. I just feel like every post I see about a seam failure is whenever an algae, usually Dino’s or Gha breaks down the seam causing it to be loose, but I guess I only look at the seam posts not the ones talking about how theirs is falling apart.

 

[tbrown]

Ah that makes sense. I just feel like every post I see about a seam failure is whenever an algae, usually Dino’s or Gha breaks down the seam causing it to be loose, but I guess I only look at the seam posts not the ones talking about how theirs is falling apart.

I have zero first hand experience though. I've just been told the seams fail because they're slipping. Several members have mentioned they can't open the doors and then their seams fail.

Coralline would be a potential "glue" though. It does make sense.

 

[Fish Fan]

To my knowledge, the floating front pane of glass is Red Sea's official explanation of the failures, but other tank manufacturers have a similar design (I believe), and I know that those who have looked into the Red Sea failures suggest that Red Sea uses inferior silicon and an improper application process, which leads to failures.

I see what you guys are saying about the coralline growing over the seam to protect it, but I'm skeptical. I'm not sure that algae growth between the seams is really what's forcing the failure, and I'm not sure if coralline growth would prevent that either way.

@UncommonSense has literally dissected old Red Sea tanks, and he's very informed on this. Maybe he's got a minute to weigh in here

 

[exnisstech]

My understanding from one of the people that helped design the Red Sea tanks was that the front panel not being supported is the main cause of the seam failures.

I have to disagree. That person must not have been privy to the type of silicon being used.

My reefer 170


There are other manufacturers using a floating front panel without any where near the number if reported failures. This is my water box 330.7 gallon 84x30x25" tank. My smaller IM20 also used a floating front panel design.

OP IME algae loves RS silicone.
My G2 reefer 300.

From what I've read if a tank like this is out of warranty RS advises to empty it. If it's under warranty it's nothing to worry about.

The seam leaks are cause by failure of the silicone. If RS took the time to dissect a failed tank they would see that. TMK they've never asked to have a failed tank returned to analyze it. But then again maybe they do know and they changed the silicone and added a Eurobrace to take the credit as the fix. We'll never know because they aren't going to publicly state the silicone is the cause. We'll know if the G3s correct the issue in a few years buy they'll never disclose the actual cause. JMO

 

[tbrown]

I have to disagree. That person must not have been privy to the type of silicon being used.

My reefer 170


There are other manufacturers using a floating front panel without any where near the number if reported failures. This is my water box 330.7 gallon 84x30x25" tank. My smaller IM20 also used a floating front panel design.

OP IME algae loves RS silicone.
My G2 reefer 300.

From what I've read if a tank like this is out of warranty RS advises to empty it. If it's under warranty it's nothing to worry about.

The seam leaks are cause by failure of the silicone. If RS took the time to dissect a failed tank they would see that. TMK they've never asked to have a failed tank returned to analyze it. But then again maybe they do know and they changed the silicone and added a Eurobrace to take the credit as the fix. We'll never know because they aren't going to publicly state the silicone is the cause. We'll know if the G3s correct the issue in a few years buy they'll never disclose the actual cause. JMO

I trust your experience. Like I said no first hand experience for me. The gentleman that told me this was one of the engineers that was on the design team.

 

[EnterName]

To my knowledge, the floating front pane of glass is Red Sea's official explanation of the failures [...]

Imagine working at RedSea and being tasked to fix the seam failures and you come up with Gen3 (eurobracing and more silicone) instead of a cheap piece of wood or aluminum below the floating glass panel as a fix

Their G3 design choices don't make any sense if the floating front pane really was the issue.

 

[UncommonSense]

but other tank manufacturers have a similar design (I believe

Yup, Fiji Cube comes to mind, such as a local reefing buddy’s Fiji 95INT:

Now, let’s use the above 60”x24”x16” tank as our example to explain why the floating front pane is actually very doable…

Glass:

— 60”x16” of 12mm (~1/2”) thick glass in the floating viewing pane = ~6.667ft2…

— 6.14lbs per-ft2 for 12mm glass, so <41lbs for the whole viewing pane…

Structural silicone seams holding glass to tank:

— 59” long horizontal seam, 2X 15.5” tall vertical seams… 90” of seam in total

— 90” of structural seam is 1/2” wide… so 45in2 of structural silicone…

The physics:

— any silicone worth using for tank building will be good for 200+ pounds per-square inch in “lap shear” (parts sliding, like the floating viewing pane trying to fall off), and typically at least double that in tension (water pressure trying rip tank apart)

— Given that we have 45 square inches of structural silicone seam, at say, 200PSI of lap shear strength (45X200); we find ourselves sitting right at 9,000lbs of rated silicone strength, holding up a <41lb glass pane!

I see what you guys are saying about the coralline growing over the seam to protect it, but I'm skeptical. I'm not sure that algae growth between the seams is really what's forcing the failure, and I'm not sure if coralline growth would prevent that either way.

Coralline algae definitely does seem to slowly creep in under the Red Sea silicone…

Here’s the edge of a 15mm short side pane I just cut into eurobracing glass, prior to cleaning off all the old silicone… this would be as viewed from the tank interior, examining a side pane’s vertical seam:

@UncommonSense has literally dissected old Red Sea tanks, and he's very informed on this. Maybe he's got a minute to weigh in here

I have indeed… In fact, I’ve done destructive failure analysis on both G1, and G2 tanks!

For anyone interested:

G1 Reefer XL425 autopsy

G2 Reefer XL525 autopsy

 

[Fish Fan]

Yup, Fiji Cube comes to mind, such as a local reefing buddy’s Fiji 95INT:

Now, let’s use the above 60”x24”x16” tank as our example to explain why the floating front pane is actually very doable…

Glass:

— 60”x16” of 12mm (~1/2”) thick glass in the floating viewing pane = ~6.667ft2…

— 6.14lbs per-ft2 for 12mm glass, so <41lbs for the whole viewing pane…

Structural silicone seams holding glass to tank:

— 59” long horizontal seam, 2X 15.5” tall vertical seams… 90” of seam in total

— 90” of structural seam is 1/2” wide… so 45in2 of structural silicone…

The physics:

— any silicone worth using for tank building will be good for 200+ pounds per-square inch in “lap shear” (parts sliding, like the floating viewing pane trying to fall off), and typically at least double that in tension (water pressure trying rip tank apart)

— Given that we have 45 square inches of structural silicone seam, at say, 200PSI of lap shear strength (45X200); we find ourselves sitting right at 9,000lbs of rated silicone strength, holding up a <41lb glass pane!



Coralline algae definitely does seem to slowly creep in under the Red Sea silicone…

Here’s the edge of a 15mm short side pane I just cut into eurobracing glass, prior to cleaning off all the old silicone… this would be as viewed from the tank interior, examining a side pane’s vertical seam:

I have indeed… In fact, I’ve done destructive failure analysis on both G1, and G2 tanks!

For anyone interested:

G1 Reefer XL425 autopsy

G2 Reefer XL525 autopsy

Well said, J., thanks for your help

 

[breathing underwater]

Yup, Fiji Cube comes to mind, such as a local reefing buddy’s Fiji 95INT:

Now, let’s use the above 60”x24”x16” tank as our example to explain why the floating front pane is actually very doable…

Glass:

— 60”x16” of 12mm (~1/2”) thick glass in the floating viewing pane = ~6.667ft2…

— 6.14lbs per-ft2 for 12mm glass, so <41lbs for the whole viewing pane…

Structural silicone seams holding glass to tank:

— 59” long horizontal seam, 2X 15.5” tall vertical seams… 90” of seam in total

— 90” of structural seam is 1/2” wide… so 45in2 of structural silicone…

The physics:

— any silicone worth using for tank building will be good for 200+ pounds per-square inch in “lap shear” (parts sliding, like the floating viewing pane trying to fall off), and typically at least double that in tension (water pressure trying rip tank apart)

— Given that we have 45 square inches of structural silicone seam, at say, 200PSI of lap shear strength (45X200); we find ourselves sitting right at 9,000lbs of rated silicone strength, holding up a <41lb glass pane!



Coralline algae definitely does seem to slowly creep in under the Red Sea silicone…

Here’s the edge of a 15mm short side pane I just cut into eurobracing glass, prior to cleaning off all the old silicone… this would be as viewed from the tank interior, examining a side pane’s vertical seam:

I have indeed… In fact, I’ve done destructive failure analysis on both G1, and G2 tanks!

For anyone interested:

G1 Reefer XL425 autopsy

G2 Reefer XL525 autopsy

Agree on your analysis. As an architect by profession: silicone structurally supported glass is widely used in glass high rise facades, and can be engineered to handle these loads outdoors through seasons, wind and earthquakes as well as gravity for 70+ years, many dozens or hundreds of feet up in the air. Properly specd and applied silicone should not fail in this mode on a fish tank.

Most likely the algae has nothing to do with it. It's just opportunistic once a paper thin separation forms, and there's a spot for it to grow no herbivores can reach. So it shows up at the leading edge of the failures quickly, giving the impression it's 'eating into' the seam.

 

[UncommonSense]

My understanding from one of the people that helped design the Red Sea tanks was that the front panel not being supported is the main cause of the seam failures.

They may have genuinely believed it!

Several members have mentioned they can't open the doors and then their seams fail.

I don’t doubt that these particular stands were insufficiently built, and/or were suffering from progressed water damage, leading to the bottom pane being unsupported in the center…

It certainly isn’t good to have the bottom pane of a rimless tank unsupported, and RS did actually send out a cute little removable aluminum bar to stick front-centered in the sump compartment of the G2 XL525 I broke down, among other larger models from what I understand… this may or may not have been a red herring to compensate for the actual issue at hand: the silicone itself!


To explain further:

— keep in mind when visualizing where force is going that glass does physically bend when a force is applied, it can even be visually apparent, without using precision measuring tools! (Eurobracing not only ties the panes together in the top corners, but functions like an I-beam to resist glass deflection [bending])

— silicone is extremely strong in shear and tension, but very weak in peel; an uneven force localized in one small area, vs. evenly distributed! (Some brands often aren’t brave enough to list their Peel per Linear Inch [PLI] numbers; those that are tend to land between 24 and 44 pounds per-inch)

— the baseline safety factor (how many times stronger is a thing than is absolutely necessary to not just fail immediately in optimal conditions) I typically see in aquarium building is 3.8… not one larger g1 or G2 Red Sea tank even hits that minimum for the bottom pane thickness, specifically (bottom pane thickness dictates bottom structural seams thickness with a rimless tank)… G1 XL425 (10mm bottom) 2.1SF, G1 450 (12mm bottom) 2.7SF, G2 900XXXL (19mm bottom pane) 3.53SF, G2 525 XL (15mm bottom pane) 3.55SF… (not all of these are true to the mm in thickness; most panes are at the thinner end of allowable tolerance to be legally advertised as XXmm…)

— now imagine that the silicone being used is significantly weaker than that in the above listed metrics; any other irregular load path caused by a defect in support, or tank design will be exacerbated!


this is why we see top-corners and bottom-center failures… the long viewing pane, with nothing to support it from bending from the top-down (unlike the long rear pane, which has a glass overflow box supporting the center)!

The viewing pane deflection (bending) starts to peel the tank apart from the top-down, starting at the inside of the seam, radiating out… sans for the bottom-center; they usually fail from the inside out….



TLDR; the tanks were designed down to a price, then an abnormal two-part, faster curing silicone was used to assemble them… based on my experience taking them apart, this silicone is shockingly weak… it barely sticks, peeling by hand in many areas, and strips from between panes can just be torn apart with two fingers pinching each side…

 

[UncommonSense]

Most likely the algae has nothing to do with it. It's just opportunistic once a paper thin separation forms, and there's a spot for it to grow no herbivores can reach. So it shows up at the leading edge of the failures quickly, giving the impression it's 'eating into' the seam.

Beyond the silicone being surprisingly low-performance from the perspective of just tearing pieces apart, I have a few theories… the leading one being plasticizers in the two-part silicone Red Sea uses…

Some plasticizers in some silicones are there for application reasons… but others, with little to no benefit, can be added simply because they are less expensive, and serve as filler material!

Saltwater is a very harsh environment for many materials to survive in… plasticizers slowly leeching from the silicone would create a surprisingly similar pattern of partial adhesive, partial cohesive failure to what I’ve observed on each breakdown so-far…