pepper'scove

Well, I just tested for ammonia and got nothing... I'm wondering if it's just scum coming off of the internals of old equipment. Anyway, didn't solve my problem, but I ruled out another potential issue. I'm determined to solve this! At this point I'm thinking that chemical residue and scum from old equipment was the cause the first go round and this time it's mostly scum on old equipment dissolving back into the water. I'll be gone all next week for Spring Break and then will resume testing the following week. Anyway, the quest continues!

At this point you're basically running a fresh water tank without any way to build a biological filter...I have to agree with Marc, it's a likely a bacterial bloom of some kind.

From About.com on fresh water aquariums: "Bacterial Blossom - Often cloudy water doesn't appear the instant an aquarium is set up. Instead it appears days, weeks, or even months later. In these cases the cause is usually due to bacterial bloom. As the new aquarium goes through the initial break in cycle, it is not unusual for the water to become cloudy, or at least a little hazy. It will take several weeks to several months to establish bacterial colonies that are able to clear wastes from the water. Over time that cloudiness will resolve itself."

Blake,

I would tend to agree with that statement, but with no detectable ammonia, nitrite, or nitrate in the tank, how could it be bacterial? If somebody could explain that mechanism to me then I would try to figure out a new way to test or just believe that this would self resolve. What I want to make sure of is that this doesn't happen after I have setup $1000s of dollars of equipment and biologicals. If I can determine its a bacterial bloom then I'd be happy since I know that a good cycle will fix my "problem" and I'll be good to go. However, if it was an issue with my silicone, chemicals in the solvent used to glue the pipes together, or some kind of rusty equipment, then I will have a problem on my hands. If I get all the way to go time and it's an unresolved equipment or materials issue then it becomes a bigtime problem. Since I resiliconed the tank myself (with Momentive 100 Series silicone that's FDA approved for food storage) and since the first time around I could easily have had primer in my drain and return lines, and since as you guys are asserting my tank is open for any bug in the world to crawl in and die in the tank or otherwise muck things up, I need to ferret out all the possibilities. Basically I want to have every reason to believe that my tank will survive. I believe it will and while I tend to think my issue was dissolved scum, I would be just as happy if someone could help me prove that it was a bacterial bloom. Again, as always, thanks guys!

Well in my business (civil engineering) I know there are test that can be ran on well/storage tanks/private water systems to check for bacteria. The tests aren't really expensive, but I don't know if these test check for the same kind of bacteria that cause bacterial blooms in aquariums. What I do know is in a private water system feed by a well with a storage tank open to the air (has to be open to the air to allow large volumes of water to drain out to meet fire demand) bacteria will form in the tank and pollute the entire system unless a chlorine dosing system is implemented.

As far as how bacteria show in the tank when there's no ammonia, nitrite or nitrate, I have to admit I don't know enough about water chemistry to give a valid explanation. What I can say, based on my own experiences, is that a fresh water tank can have a bacterial bloom and still read 0 ammonia, nitrite and nitrate. It happened when I set up a 10 gallon for my wife a few years ago. She wanted a Betta tank, so I set up a 10 gallon for her, cycled the tank using sponges with airstones to create the biological filter. I also ran one of those hang on the back style floss and charcoal filters on the tank. The tank cycled fine, put the fish in and everything was good for about a month. Then one day the water looked hazy. The next it got worse and so on until you couldn't see from one end to the other. Ammonia, nitrite and nitrate all read zero (may be the test kits were bad or out of date, I don't know). I started doing heavy water changes using RO/DI water and mixing in a little baking soda, a little salt mix from my saltwater tank and some epsom salts (found this mix online for cichlids as I remember). I don't know if it was the water changes, the water mix or just time for the biological filter to fully establish, but in about 2 weeks the water was crystal clear again.

Huh, so I guess that is probably what's happening to me. I don't know that much about freshwater tanks at all. Maybe the reason they use a little salt in freshwater aquariums is because of the cloudiness issue I'm having. However, I do have chlorinated city water in the tank right now. Then again, I had a bit of charcoal running in the tank and that could've sucked up all the chlorine (I have allergies so I can't really smell the water right now...). But at a gut level what you guys are saying makes sense. Maybe after Spring Break I can just add a little bit of salt to my water and then once the water gets murky/cloudy, just sit back and wait. If it self fixes then it's almost certainly a bacterial issue.

When exposed to air, chlorine dissipates out of the water. Municipal and private water systems have to continually dose to keep the concentration at the proper level to kill the bacteria. The storage tanks you see on hill sides or large stilts isn't for normal daily use demand. Instead it provides both the volume and the pressure necessary to provide fire protection demand. Some systems are set up to use the storage tanks for peak demand also, but not all of them. The point is, the water in the tank can sit for hours or it can sit for days or weeks (with very little turn over). The dosing systems have to be continuously check and adjusted to keep the chlorine level high enough to kill bacteria but not cause harm to drinkers of the water.

I could be wrong, but I think your tank will probably be fine, though, as I'm upgrading to a larger tank myself, I can understand your concern and desire to "get it right" the first time. If you really want to go the route of getting the fresh water to stay clear for any length of time, you're going to need to establish a biological filter. In fresh water, the easiest way is to get a couple of sponge filters powered by air stones. You could also get one of the hang on the back type filters with the inserts that allow a biological filter to grow on them. Use RO/DI water and look up the amounts of marine salt, epsom salts and baking soda to mix in for your volume of water. Once all this is set up let it run for 4-6 weeks. You can help the cycle along by using the "household ammonia" method and adding purchased freshwater bacteria. However, I think this is all overkill. You're not really trying to set up a fresh water system, right?. Without a proper biological filter, if you have water in a closed system (no new in/no old out) that is exposed to air, you will get bacteria in the water. The levels that are unsafe for human consumption don't even show as cloudiness. In fact, water can be very unsafe for human consumption and look crystal clear (as in mountain streams that give people dysentery). By the time you can see a cloudiness in the water, the bacteria have reached a very high ppm and without chemical interaction or a biological filter, it isn't going to get better by itself.

I know that really doesn't give you any more peace of mind so to speak, but I would say if it doesn't begin to cloud within a few minutes (hours at most) it probably isn't some pollutant, but is instead bacteria.