The nitrates are always low, I don't test before and after, rarely test. If it will help why wouldn't I do more water changes? I don't like to not do water changes because I have a lot of filtration (I also way overfilter) because not enough water changes can undo all the filtration in the world. Filtration and water changes are separate issues and only when one is not up to par will increasing the other relate to it. Filtration keep sit clean while it's in there and gets ammonia to nitrates as fast as possible and water changes keeps nitrates and many other harmful substances down and adds trace elements. The more and bigger water changes the better, period. Actually the 404 and 405 are rated 'up to' 100 gallons, which means they actually only do about 50 gallons each. I'm tellign you, the only thing listed that nots on the tank already is the 404, and there is nto that much flow in there. If I actually see a problem with their behavior of course I will fix it, but for now I will go with what I know, tons of filtration and big frequent water changes. It does not make life hard on me, it actually helps because it means the fish grow that much faster, that much bigger, have much better coloration, and have less health problems overall which means I get to enjoy them even more. I have tried the different water change schedules and the best by far looking at all of the previously mentioned things is big frequent water changes. If you are already sitting there with the tank partially empty, why not sit there a few more minutes and do that much more good for the fish.
Large, Frequent Water Changes:
I used to buy into the mindset that big water changes will screw things up, like your nitrifying bacteria cultures or the pH, stuff like that. But in fact they help and are now one indispensable aspect of my fish care. Water changes wont affect your nitrifying bacteria colonies.
The nitrifying bacteria live ON surfaces in the water, not IN the water column itself. The only thing they use the water column itself for is to spread (from the gravel bed, to the tank wall, to the biological filter, to the surface of the plants, etc). So you could (and I have) do 100% water changes and have absolutely no ill effect to your biological filtration. And as for pH, thats only a concern if your tap isnt good for your fish. Over time different things build up in the water that will change the pH. For example nitrates form nitric acid and therefore lower your pH over time. So big frequent water changes help keep the pH closer to your tap water's, so when the water changes are done there is little or no difference in tank and tap pH, whereas if you do smaller and/or less frequent water changes the pH in the tank may shift and therefore it will be a bigger change in pH when you do the water change.
The main reason to do big frequent water changes is to help dilute problematic chemicals. Nitrates are a big issue with fish. You may hear not to let them go over 40ppm or something to that effect, but that just means at MOST. But really the lower the better. As an analogy: sometimes there are limits to certain chemicals in the air for humans. So if it is bad to go outside if chemical X is over 20ppm, it still isnt good for you if they are just below that, the lower the better. So the lower you can keep the nitrates, the better for the fish. Nitrates slowly stress fish over time and can lead to decreased growth, health, and general ability to thrive. So the lower you can keep them the better. There are other dissolved organic compounds that also affect fish in the same way.
The other chemicals that are of concern are growth-inhibiting hormones that inhibit the growth of the same or sometimes similar species. The fish give these off and is evidenced by tanks with varying sized angelfish. The smallest ones are not growing in part due to the growth inhibiting hormones in the water. In nature this is good because it gives the big individuals more time to breed and produce more young before other individuals are big enough to compete with them for that right. So big frequent water changes keeps these growth inhibiting hormones to a minimum. In nature when the dry season hits, the volumes of water drop, concentrating all these chemicals even more, reducing growth, and the bigger the fish the more waste, so in nature no one needs to be growing in the dry season and therefore producing even more waste in these ever decreasing bodies of water. So it makes it ever so slightly more likely that more fish make it through the dry season. So, the bigger and more frequent water changes, the less like the dry season.
In order to breed, the fish have to be thriving, and many if not most breeders rely on water changes to help keep their fish in the absolute best condition possible. I am on well water so my tap can go straight into the tanks. It is easy to bring pH up, but it is very hard to bring it down. For my African cichlid tank I add the proper lake salts and buffer right when I start to fill the tank again so that they are dissolved as it is filled. If you need it down from your tap, you need to have it ready before the water change. This is why I carry out and highly recommend big frequent water changes at or about the rate of 50-75% weekly.
I tried this new water change schedule and what I thought was thriving before, was pretty good, but it was not thriving. I saw greatly improved growth rate, max size, coloration, fewer health problems at all, and a general increased ability to thrive.
Large, Frequent Water Changes:
I used to buy into the mindset that big water changes will screw things up, like your nitrifying bacteria cultures or the pH, stuff like that. But in fact they help and are now one indispensable aspect of my fish care. Water changes wont affect your nitrifying bacteria colonies.
The nitrifying bacteria live ON surfaces in the water, not IN the water column itself. The only thing they use the water column itself for is to spread (from the gravel bed, to the tank wall, to the biological filter, to the surface of the plants, etc). So you could (and I have) do 100% water changes and have absolutely no ill effect to your biological filtration. And as for pH, thats only a concern if your tap isnt good for your fish. Over time different things build up in the water that will change the pH. For example nitrates form nitric acid and therefore lower your pH over time. So big frequent water changes help keep the pH closer to your tap water's, so when the water changes are done there is little or no difference in tank and tap pH, whereas if you do smaller and/or less frequent water changes the pH in the tank may shift and therefore it will be a bigger change in pH when you do the water change.
The main reason to do big frequent water changes is to help dilute problematic chemicals. Nitrates are a big issue with fish. You may hear not to let them go over 40ppm or something to that effect, but that just means at MOST. But really the lower the better. As an analogy: sometimes there are limits to certain chemicals in the air for humans. So if it is bad to go outside if chemical X is over 20ppm, it still isnt good for you if they are just below that, the lower the better. So the lower you can keep the nitrates, the better for the fish. Nitrates slowly stress fish over time and can lead to decreased growth, health, and general ability to thrive. So the lower you can keep them the better. There are other dissolved organic compounds that also affect fish in the same way.
The other chemicals that are of concern are growth-inhibiting hormones that inhibit the growth of the same or sometimes similar species. The fish give these off and is evidenced by tanks with varying sized angelfish. The smallest ones are not growing in part due to the growth inhibiting hormones in the water. In nature this is good because it gives the big individuals more time to breed and produce more young before other individuals are big enough to compete with them for that right. So big frequent water changes keeps these growth inhibiting hormones to a minimum. In nature when the dry season hits, the volumes of water drop, concentrating all these chemicals even more, reducing growth, and the bigger the fish the more waste, so in nature no one needs to be growing in the dry season and therefore producing even more waste in these ever decreasing bodies of water. So it makes it ever so slightly more likely that more fish make it through the dry season. So, the bigger and more frequent water changes, the less like the dry season.
In order to breed, the fish have to be thriving, and many if not most breeders rely on water changes to help keep their fish in the absolute best condition possible. I am on well water so my tap can go straight into the tanks. It is easy to bring pH up, but it is very hard to bring it down. For my African cichlid tank I add the proper lake salts and buffer right when I start to fill the tank again so that they are dissolved as it is filled. If you need it down from your tap, you need to have it ready before the water change. This is why I carry out and highly recommend big frequent water changes at or about the rate of 50-75% weekly.
I tried this new water change schedule and what I thought was thriving before, was pretty good, but it was not thriving. I saw greatly improved growth rate, max size, coloration, fewer health problems at all, and a general increased ability to thrive.