View Full Version : Salt creep, silicone, and curing times

01-10-2013, 09:05 AM
I have a question, I have a camber in my sump not being used and I'm thinking about pumping it full of water with a spare mag 5 and using it for a UAS. My question is if I have a 40 breeder using a Mag 7 for the main flow would a Mag 5 be enough flow for the UAS to work properly? I'm using a 29 gallon tank for my sump so I have about a total of about 55-60 gallons if I had to guess and I feed 1-2 cubes a day and coral food alot.

I started using a waterfall scrubber but was unhappy with the mess it made as far as salt creep....which is why i have an extra camber in my sump.

Floyd R Turbo
01-10-2013, 09:51 AM
There are solutions for what you describe with the salt creep on the waterfall scrubber. The one that comes to mind first is the saran wrap idea. That would pretty much eliminate it.

But as for flow through, you would just need to plumb the return drain into the unused section and put the UAS screen in there. All you need for a UAS is the tank water turning over in it's general proximity.

However I do pump-feed mine (top of tank box) so I get what you're saying, I would think a Mag5 would be overkill, but hey if it's what you have why not. The more flow the better. Although if there is too much flow, your bubbles from the bubbler might not come anywhere close to the screen. There are many ways to do it.

01-10-2013, 10:17 PM
If it's true salt creep (not salt water mist) you are plagued with, try this. Take some aquarium grade silicone (the stuff that smells like vinegar before it's dry) and use your finger or a Qtip or whatever to make a thin film between the water and wherever you don't want the salt to creep to. This doesn't have to be a thick film at all, It works no matter what the thickness. It turns out that salt water does not want to wet this silicone film. What you will see is little beads of water over the silicone that do not spread. At the same time glass or acrylic will look completely transparent above the water line because saltwater wets them very effectively.

I've been doing this for years without a trace of salt creep anywhere in my system. If the film becomes damaged by abrasion or whatever just renew it with a little local touch of the silicone film.

There are a few other things that pretty much eliminate salt spray from bubbles bursting at the surface too for uncovered areas in the sump but it doesn't sound like that's the problem you are fighting. If they are give a shout and I'll fill you in on what has eliminated that problem for me too.

01-10-2013, 10:34 PM
I forgot to mention that the surfaces you apply the silicone film to need to be dry when you apply it. The silicone doesn't like to adhere to a wet surface just as the water does not like to adhere to the silicone. Just turn off you pumps for a couple minutes. Thoroughly dry and clean the surface. If you have to scrape the surface with a razor blade to get off all traces of old salt creep do that, or try a Mr Clean Magic Eraser to remove little bits of residue. In any case after the surface is clean and dry put on the silicone film. After the film is in place you can start your pumps immediately if you like. The silicone will cure properly even with water on it. In fact it requires water vapor to cure at all. The little bit of acetic acid gas that is given off by the silicone is not going to harm anything. If there were a lot of it it would drop your pH substantially but with a thin film I've never been able to detect any change.

Floyd R Turbo
01-11-2013, 07:29 AM
Non-cured silicone should never be in direct contact with water in a reef system. Bottom line. It may or may not cause problems. But I have read many a thread where people put together a tank and filled it in 72 hours and then had everything crash. There is much discussion about this on other thread and this is way off topic for this one, but after discussions with several reputable manufacturers the word is 1) use aquarium safe silicone in an aquarium (no exceptions) and 2) let it cure adequately. For construction of a tank or addition of baffles to a sump, this is generally held to be 2 weeks by most manufacturers. For an application like you are describing, I would think it would depend on how much area to do at a time. A few sq in of submerged area, probably not a big deal. The more area you get, the more you should probably wait, or split up into smaller areas a bit at a time.

01-11-2013, 07:42 AM
Aw cummon....does that mean I should stop dosing with vinegar? I personally don't so that bye the way but the point is acetic acid is regularly introduced into lots of folks aquariums in small amounts with what many consider favorable results.

I mentioned that a large amount of acetic acid would cause a problem. I also mentioned that I've been doing this thing with thin films around the rim of tanks etc. for many years. Hmmmm let's see how many? Turns out I've been doing it since 1979. Now I wouldn't doubt that any manufacturer would want to be 100% on the safe side when it comes to product liability. He certainly can't control the amount of silicone some customer might use uncured in water and moreover if someone were using that silicone for a structural reason that someone would be pretty foolish because it takes a long time for the silicone to be fully cured and reach it's maximum strength.

For me if a salt creep pops up do I want to shut down my tank for 2 weeks to let the silicone film fully cure or would I rather take the decidedly small/nearly negligible risk of introducing a very small amount of acetic acid into my tank. I have always chosen to stop the salt creep. It's worked. Others can certainly do whatever they think is proper.

Floyd R Turbo
01-11-2013, 08:09 AM
I'm not saying that it is a big problem above the water line. But you suggested that "silicone will cure properly even with water on it" and while it is probably not a big problem for a small area like you describe, if someone were to read that and smear silicone all over their very large sump in one shot, let it skin over, then turn the pumps on and submerge several square feet of silicone, they could experience a problem. Sorry - I just look for the worst case scenario, so I didn't mean to say you should never do it like you say - just withing reason. Dosing vinegar is one thing (5% AA), but silicone contains a much higher concentration of AA, so much so that it can easily cause burns. You don't hear about people dosing Glacial AA (99.9% pure) into their tanks.

Structurally, I have read 48 hours cure time to water test, 72 hours to useable. Generally in non-reef aquaria it is not a problem from this point forward. But I have read many threads where people siliconed in a non-pressure baffle into a sump, let it cure for a few hours, then fired the sump up and lost every coral within a few days. Therefore I prefer to take the stance of not recommending the use of non-cured silicone in a reef system, it's just as simple as that. At least not in a significant amount. Even in a FOWLR system that has inverts and delicate micro life on rocks can be affected if uncured silicone is used, or more correctly, if too much is used.

So I will edit my post above yours to be a little less aggressive on the curing stance...but I think if doing this to sections that would be immediately submerged, doing it in sections would be wise (especially if you have a large area to do, or many very expensive corals!)

01-11-2013, 08:12 AM
I agree. 100%