Are Water Changes Actually Necessary?

[jpappy789]

Or you have a DSB running.

But there are so many things we cannot test for so nitrogen levels are just the tip of the iceberg when it comes to dissolved organics.

 

[Jannika]

My water isn't chlorinated and I leave the bio-media in the filter as you're supposed to so that the beneficial bacteria colony isn't depleted too much.

Without touching the bio-media, just changing the filter cartridge was enough to cause a mini-cycle in my tank.

 

[GoldLenny]

A large majority of the nitrifying bacteria reside in your substrate, as well. I see you mentioning ammonia and nitrite levels, have you measured nitrate levels at all? These are just as important as the first two (and water changes are the ONLY thing keeping nitrate levels down, unless your tank is HEAVILY planted)

This is only true when a tank has a UGF filter system. Nitrifying bacteria are aerobic bacteria, meaning they need HIGH oxygen levels in their water in order to thrive. With a UGF filter, where the filter is pulling the water down through the gravel and then returns it back through the uplift tubes, this would be true BUT for all other filters systems, the gravel, other than the very top surface areas, gets very little oxygen compared to other areas of the tank and especially when compared to all of the surface area on other filter media. A single section of filter floss pad or even a single piece of specialized biological filter media that is very porous with miles of microscopic tunnels, has more surface area than all of the gravel combined. Further, the nitrifying bacteria are going to set up home where the food is and the filter media has all the water (with ammonia, nitrites, oxygen) flowing through it on a constant and rapid basis compared to the gravel which just has some of the water touching it as it circulates.

Dr. Tim Hovenac, the inventor of the BioWheel and many other patented products like Dr. Tim's One And Only live nitrifying bacteria (even did his PhD on nitrifying bacteria in aquaria) has said and written this many times over the years... so it's not just me saying it.

 

[GoldLenny]

Without touching the bio-media, just changing the filter cartridge was enough to cause a mini-cycle in my tank.

Is that a question? If it is, then yes, any time you trash a percentage of your filter media or do anything else that trashes a certain percentage of your nitrifying bacteria, it will put a tank into a mini-cycle.

MOST of the time, this mini-cycle doesn't even show up on our test kits because the levels of ammonia and nitrite stay pretty low, but in newly set up tanks, tanks with heavy bioloads, the ammonia or nitrite level can become more of a concern. It also depends on how well your nitrifying colonies recover and rebound. Nitrifying bacteria are capable of doubling their colony size every 24-48 hours in good conditions with high O2 and moderate to high pH level water. In very warm water or other water with lower levels of dissolved oxygen or in tanks with very low pH (low 6's or lower), the N-bacteria take longer to multiple.

For folks with high pH water, even low levels of ammonia can cause problems to their fish. For example, water with a pH of 6.5 can have ammonia levels of 4+ ppm and not be a toxicity problem but for water with a pH of 8.0+, even 0.25 ppm can be a toxicity problem... once again depending on the temperature of the tank.
http://dataguru.org/misc/aquarium/AmmoniaTox.html#ammonia3ppm
http://www.thekrib.com/Chemistry/ammonia-toxicity.html

While biological filtration media is very good and houses a LOT of nitrifying bacteria, if folks don't do proper maintenance on their filters, including sloshing the bio-media around in removed tank water to get the big stuff off of it, the bio-media can easily become clogged with detritus and not be as effective. The N-bacteria need good oxygenated water getting into the bio-media for they to do their jobs. If the bio-media is coated in detritus, then the N-bacteria will start to die off. See my blog/article "Filter Cleaning And Maintenance" a copy of which is also hosted on AC, for more info.

 

[J double R]

This is only true when a tank has a UGF filter system. Nitrifying bacteria are aerobic bacteria, meaning they need HIGH oxygen levels in their water in order to thrive. With a UGF filter, where the filter is pulling the water down through the gravel and then returns it back through the uplift tubes, this would be true BUT for all other filters systems, the gravel, other than the very top surface areas, gets very little oxygen compared to other areas of the tank and especially when compared to all of the surface area on other filter media. A single section of filter floss pad or even a single piece of specialized biological filter media that is very porous with miles of microscopic tunnels, has more surface area than all of the gravel combined. Further, the nitrifying bacteria are going to set up home where the food is and the filter media has all the water (with ammonia, nitrites, oxygen) flowing through it on a constant and rapid basis compared to the gravel which just has some of the water touching it as it circulates.

Dr. Tim Hovenac, the inventor of the BioWheel and many other patented products like Dr. Tim's One And Only live nitrifying bacteria (even did his PhD on nitrifying bacteria in aquaria) has said and written this many times over the years... so it's not just me saying it.

:worthy: I am not worthy!

 

[Jannika]

Is that a question? If it is, then yes, any time you trash a percentage of your filter media or do anything else that trashes a certain percentage of your nitrifying bacteria, it will put a tank into a mini-cycle.

I was just clarifying of my earlier statement, since the poster appeared hell-bent on changing those filters as per the manufacturers instructions.

 

[SweetieAngel]

Well obviously you have to change your filter media at some point so if this is enough to cause a mini-cycle isn't that inevitable?

 

[knifegill]

No, you don't ever have to change your filter media. Some of my sponges are five years old now and working like new. I have no reason to throw the babies out with the tankwater, if you catch my drift. Just rinse off the prefilter and the flow is good as new. Occasionally I do have to dip the sponges into a bucket of tankwater to cut back on the sludge a bit.

I just can't believe that this thread had so many people trying to encourage the lazy and careless approach of trying to create a balanced system without water changes. That's called stagnation. Where do you think the food you feed your fish goes? TDS! Mzjinxd nailed it on page one yet the thread kept rolling as if the answer weren't there at all. Shame on lazy people who think they can recreate the vastness and complexity of nature in a glass box with a few plants. You will always need water changes to maintain the health of your system. Deal with it.

If someone in the future designs a ridiculously expensive machine that rebuilds water constantly back into its fresh and new form, well that's different. But for now, water changes are the simplest and best way to keep TDS down.

 

[archer772]

I agree WC's are needed but at what percentage and what interval. I really dislike it when it is said that 50% WC's have to be done every week because everybodies tank is not the same as everyone elses tank.

I here it is needed because my fish are happy when I do them, can somebody tell me how you can tell if a fish is HAPPY.

I also here my fish grow faster when I do them but what is the growth rate in the wild, are we forceing faster growth than nature does.

I here my fish spawn more when I do the 50% WC's but can someone tell me how often fish spawn in nature, are we forceing them to spawn more often.

I wont say this is true for everybody but I know my brother does about 15% monthly WC's on his tank and his Fronts are 15 years old and going strong.

 

[GoldLenny]

Well obviously you have to change your filter media at some point so if this is enough to cause a mini-cycle isn't that inevitable?

Not for many, many years. See my blog, "Filter Maintenance And Cleaning", which a copy of my blog article is also hosted here on AC, and it explains how you should properly clean your filter media so that you remove the bulk of the detritus but leave the bulk of the nitrifying bacteria alive and well on the filter media so that there is minimal disruption to your N-bacteria colonies, meaning minimal chance of a mini-cycle. Yes, if you kill off 10% of your N-bacteria, you could have a 10% spike in ammonia but the N-bacteria will start reproducing to keep up with the spike in available food and you'll never likely notice anything wrong. Now, compare that to if you trash 100% of your N-bacteria colony, where you'll see a bigger spike in ammonia/nitrite and if you are subjecting your fish to ammonia/nitrite spikes over and over and over for many months and/or years, it starts to take it's toll on them. Compare it to smoking a cigarette... smoking one and you'll cough and gag but you won't likely get cancer or lung disease. Do it over and over and you likely will. The same thing for ammonia/nitrite and it's effects on a fish's gills and other organs.