Drawing and question about salt creep mechanics, sealed reef

[brandon4291]

Hello Craig and Randy,

I have a particular problem I can't get a hold of, its concerning salt creep and how to prevent it.

Long story short, much experimentation has gone into sealing some of my systems to prevent salinity shifts in tiny reef aquaria. The rubber weather stripping sits on the inner diameter of the tank, and fits rather tightly all the way around. it is glued to the underside of the glass lid I use to cover the system. I must use a small fan in the rear which is constantly on to control temp spikes, as a sealed reef is the hardest to cool (cooling of the outer tank walls works fine)
My question is, I get no salt creep in the front of the tank where there is no fan, but I still get some in spite of the good sealing in the rear where there is alot of air current over the rear seals. And, I keep the water line LOW so the curves of the water at the 90 degree points won't touch the seals to start a wicking action. How am I getting creep to jump past a half-inch gap of air and onto the outer seals? I could understand if it were over-filled and just leaking out and drying, but Ive kept the water line low and it still creeps in the back.

From the art illustration, what can you guys make of the mechanics of salt creep in this little system?

Sure appreciate your time and efforts,

brandon 429

 

[Chucker]

You note that the fan is always on.... I'd bet when there is temperature differential in the room when the lights are off, that you get condensation on that rear pane. The condensation could easily wick through the rubber and cause the creep you're seeing.

 

[brandon4291]

never thought of that Chucker, the only thing I would still wonder is that the condensation should be FW and not yield such a thick salt coating on the rear seals--or at least close to FW I would think since evaporation wouldnt carry any salts out with it.
Do you think I just need to work on the rear sealing better? I was hoping to have it sealed so well that even heavy air flow (fan is currently on low) wouldnt cause a change in the internal system.

SW is a pain in the butt to seal!!! Thanks for your response,

brandon

 

[brandon4291]

Chucker, thought about what you said for the evening and it became clear. even if its not the condensation itself causing the caking around the outer seals, this is likely coating the inner parts of the seals and the otherwise dry acrylic wall leading right to the top of the SW---enough for capillary action to start and then the SW works itself right through the lid/tank seam. Driven by evaporation of that water wick on the outside, and also fueled by the condensation that collects on the rear pane due to increased cooling at night.

Good call

b

 

[randy holmes-farley]

That sounds like a reasonable explanation to me. Even without the fan or condensation, I get salt creep up the plastic sides of my refugia. I don't see why it wouldn't also happen in this case, perhaps spurred on by surface water waves caused by the fan.

 

[Andersen]

Ahh, finally something I can answer

It sure has something to do with the fan. I have two IKS Turbo pumps in my tank. These are external pumps placed on top of the tankside. The problem is the way they´re build, it takes the air and push it out and downwards round the pump, this is due to a small fan which is build inside the cabine. And guess what, I got salt creep just around these pumps, and this is the only place the salt creeps in my tank.
I have thought about removing the top of the cabine to let the air go upwards insted, but I´m not sure if the will have any influence on the pumps, as the point is to cool down the pump.

I can add an picture later, if anyone wants to have a look.

Greets
Kim Andersen

 

[brandon4291]

Sure Kim, Id like to see a picture of your tank. Salt creep is a pain!! If I have to weld the lid on with epoxy I WILL find a way to stop it ! jj

 

[brandon4291]

What I want to do now is forego the larger fan that blows on the back of the whole unit, and try a few DC fans wired in parallel that just blow on the lighting itself, mounted in the miniature canopy, above the seam where the salt creep originates... maybe less air flow over that seam would help.
Randy now I am beginning to think it may be nearly impossible to seal a seam that needs to be lifted from time to time (non-glued). No matter how hard its pressed, if its rubber pressed on glass there will always be tiny pathways for water to seep through. Rapid fanning/evaporation just waits for a chain-link of water molecules to pull it all out of the delicate reef water column. Uggh, the pains of half-gallon aquariums Ill bet theres some way to get it fixed and still cool the system effectively... nothing a little tine won't reveal.


b429

 

[Andersen]

Brandon, here are some pictures of the salt creep I mention from the IKS pumps.
http://akvariet.terrabyte.dk/salt/page_01.htm
Notice the salt creep underneath the pumps and on the brackets.

If you want to see pictures of my tank, I´l soon be uploading some new ones to my site, but here are some older from last summer:
http://akvariet.terrabyte.dk/images/akv ... age_01.htm
http://akvariet.terrabyte.dk/images/110 ... age_01.htm