Old tank syndrom?

[Oohitsae]

I've seen people mention "old tank syndrom" a lot recently, but have never really had it explained.

Can someone tell me, what it is, how to prevent it, and how to fix it if it does happen?

Thanks!

 

[marsh]

Someone broke it down to me like this: some fish survive in totally neglected tanks for 6-12 months or longer. They basically adapt to the horrible water quality over time and "tough it out"

If those hardened and neglected fish were put into a pristine tank overnight, the shock alone would kill them. So rather than simply clean up their environment as best as possible, the gentle way to handle such environments is to make slight improvements over a longer period.

Ie: 15% water changes daily over a week instead of a 50-75% water change

 

[Taiken5968]

Here is something that I have been told too.the old tank runs so smoothly and doesn't have many problems so some people over feed or start overstocking. Then you get a build up of toxic stuff relatively quickly.

 

[Andy Sager]

The best way to avoid old tank syndrom is to get into a habit of doing water weekly changes on a schedule and keep to that schedule. For example, 10%-15% water change every Saturday!! By keeping a schedule, you help avoid any accumulation of detritus or nitrates in the water. Remember to be cleaning different areas of your gravel with every water change as well. You must keep "gunk" from clogging up the gravel. I once pulled a pint of live tubifex worms from a customer's undergravel filter plate because he failed to do this. He was keeping Discus and was not keeping track of how much worms he was feeding or his fish were eating. It was not a pretty site.

Hope this helps

 

[aqua_chem]

I've seen at least three things described as "Old Tank Syndrome". All of them relate to poor water change habits and poor tank maintenance/technique.

First, marsh mentioned, is the accumulation of nitrogenous waste. Without water changes, it would not be possible to remove nitrates (excluding plants), so they will build up to toxic levels eventually. Sometimes when this happens the fish will adapt to the polluted waters, but weaker fish and new fish wont be able to adapt and die. Whether or not a large water change will affect this problem isn't clear.

The second problem often rolled into 'Old Tank Syndrome' is the tendency for tanks to acidify over time. The nitrification process that breaks down ammonia into nitrate also acidifies the water. Over time, this can potentially drop the pH very low, potentially into hazardous levels for the BB and livestock. The effect is pronounced in poorly buffered and overstocked tanks. A large water change in this case could potentially be hazardous to the fish.

The third case occurs when tanks are 'topped off' with tap water after a significant amount of water has evaporated. Remember than when water evaporates, only pure water is removed; the minerals in the water remain. Adding water adds both water AND more minerals, so that the resulting tap water has more minerals than initially. Short term, this isn't that much of a problem, but if this is repeated several times, the mineral content of the water will increase steadily. This can unfortunately go on for some time, leading to increasing salinity. This by itself isn't much of a problem, as most fish can adapt to it. The problem comes when you do decide to do a water change, and you rapidly change the mineral content/TDS of the water. This can create a potentially hazardous situation for this fish, which is likely to blame for the die-off that is sometimes seen after a water change in these circumstances.

 

[Oohitsae]

Thank you guys so much for the explanations!!!

Sounds like I don't have much to worry about.