Condensation on bottom of tank?

[jdamon]

Hello everybody, I have a 75 gallon oceanic tank with an overflow box on one of the narrow ends of the tank, in the middle. That leads to an amiracle wetdry that I gutted and use as my sump. I also have a small refugium tucked underneath the tank, on a shelf. Both of these are not covered, and I am wondering if I have a leaking bulkhead, or a condensation problem. The underneath of the tank is covered with salt, and I have seen what I think is condensation during the night. I thought the salt would not evaporate though, so its weird that the bottom of the tank is covered in salt..... Any input would be great, thanks in advance.

Jeff

 

[Len]

My estimation is it's a leak in a bulkhead. I have never heard of condensation building up under tanks, even in the most humid of conditions. For sure it's never happened to me. Is the entire bottom of the tank speckled with water droplets, or is the water and salt creep on specific areas of the underside?

 

[jdamon]

Thanks for such a quick response Len! The entire underneath is covered in salt. Its weird. When I had a cover on the sump, that would always have water covering the underneath of it, and I always assumed it was condensation. The bulkheads have salt creap around them, but there is not a noticable drip. No one has ever seen this?

Jeff

 

[jdamon]

I forgot to add that the underneath of the tank is never wet during the day. The salt is still there, but no water. I have seen it covered in dropplets late at night.

 

[Len]

I've never seen condensation on tropical tank, especially to the degree you're describing. If I was a betting man (and I am ), all my money would be on a leak somewhere. I've seen plenty of leaks on bulkheads that look like what you've described: salt creep around the fitting extending inches away, but no visible water. The reason is the water is seeping out at such a slow rate that it's evaporating almost as soon as it's exposed to air, leaving behind the growing salt creep.

Check your fittings .... i think you'll find the problem there.

 

[Robin Goodfellow]

hi.
If it is condensation, it will evaporate without leaving residue, since it is "distilled." The fact that there is salt on the bottom indicates that the "condensation" you see is not condensation, but tank water. This means that there is a leak.

Clean out all the salt creep and try to find where the saltwater leak from. You need to make sure the leak does not jeopadize the structure of the tank. Better be safe than sorry.

 

[jdamon]

Thanks Len, will do. I may have to buy some new ones. Anyone have an opinion on the best manufacturer?

 

[Len]

The ones sold by online vendors are all good. Just make sure that there is no particles between the tank and the gasket. And of course, tighten firmly

I think Mike Kirda has some heavy duty bulkheads that he wants to sell. Maybe PM him (mkirda) and see if they're still available.

 

[dtiedke]

Do you have a fan on the sump? I have just set up my sump in a small closet, and have a fan blowing on it from about 3 feet away from it. The fan is a small clip-on type, and really moves the air....

Anyway, a week or so later I noticed that everything (and I mean EVERYTHING) has a light dusting of salt on it. Mostly on the fan itself, all the equipment on it has it as well. Turns out that the water entering the sump is misting a bit, and the fan was blowing that mist (with the salt in it) around the room.

Thought I would include that as a possible suspect....

Dave

 

[jdamon]

I do have a fan blowing on the external pump down there. Good call. I think there is a problem with the bulkhead(s) though as well. I am familiar with the "dusting" you describe, and I have some of that too, but this is "wetter" for lack of a better word to describe it. I had one of these bulkheads crack initialy when I put it all together, and I replaced it. I am thinking they are of inferior quality. Can anyone recomend a good bulkhead manufacturer?

Jeff

 

[jdamon]

I think I figured out what is really causing the "condensation." So, the skimmer collection cup has an air escape hole in it, and this is only 6-7 inches from the bottom of the tank. I think this is whats causing all the problems. I just bought a couple of those old school carbon/floss cartridges that are used to catch ozone, so i should know if this works by tomorrow. Thanks for everybody's input.