Andy Sager
Aquarium Advice Addict
You would think....
I used the charcoal example because when we had this discussion, carbon wasn't being used. Both charcoal and carbon act as a filter/ purifier so except for some certain exceptions, it's not a bad thing to use.
Topping off from evaporation: There are certain minerals that don't evaporate when the water does. Salt, (NaCl) is one of them. So as your water evaporates, the salt level increases allbeit slightly in a freshwater tank. When you add water for evaporation, you are adding some more salt to your water through the chemicals you are using to dechlorinate/ dechlorimine the water. Once again, this change may very well be insignificant to the overall volume of water and the fish, depending on the type, may show no ill effects of this change.
Another thing to remember is that your system is a living breathing system. Your bacteria beds are constantly growing and shrinking depending on the bioload. Removing larger volumes of water also can create drastic changes in this area too. Say you have just inadvertently overfed your tank and there are pockets of uneaten foods that your bacteria bed is growing to adjust to the ammonia load. You may or may not see this change in an ammonia reading. Now say that bed has blossomed and you do a large water change so that the ammonia level has now decreased drastically and you are now starving all those new bacteria that were produced to reduce the ammonia load. What do they do? They die off to a manageable level once again thereby causing a slight rise in the ammonia level and the cycle goes on. I used excess food in this example but a dead fish as well as other natural occurances can be substituted for the food. The bottom line is that there are changes that you are not always aware of that are occuring in your tank that larger water changes do effect. How much it effects the fish in the system varies from specie to specie.
In all honesty, I prepare the water I am going to use for a water change the day before I change it. Right now I am on well water so I don't add anything to it, just salt. When I had my hatchery, I had a Culligan carbon filter that removed the chlorine/ chlorimine from the tap water and we used that water straight from the hose. No other pre-prepping required. When I had my wholesale house, we used a Culligan filter with a PH adjuster and used the tap water straight from the filter to do water changes. (The PH adjuster was because we were importing a lot of fish from S. America and did a slow change to our higher PH water here in FL.) Once again, smaller changes more frequently enabled these fish to adapt better to the changes.
And that's really the bottom line. The smaller the changes, the easier it is for the fish to adjust to the changes no matter what they are. I know everybody has different experiences with their tanks and I am usually a proponant of "If it ain't broke, don't fix it!" except when it comes to water changes. In a saltwater tank, there are natural items that can be grown in the tank and consumed by the fish that replace the needs for water changes. What I have found is that fish kept this way over long periods of time, do not adapt well once moved to a new system. In my last move, I gave my fish to my friend's store to hold while I made my move (some 200 miles away.) I had had the three fish he was holding for a minimum of 8 years ( the longest being 13 years) so obviously, whatever I was doing must have been right. You'd think so wouldn't you? None of my fish lasted more than a week at the store. I supervised EVERYTHING so I know that everything with the change was done correctly yet they still didn't survive. In my freshwater tanks, I changed the water all the time. Whether from habit or whatnot, I had no problems with them. So that's why I still say that doing smaller changes more frequently will have a better effect on the fish than larger changes less frequently.
Be assured that I take no offense to your questions. I am not a scientist (& I don't play one on TV ) so I can't give you all the scientific reasons why things happen. What I am is a guy who was trained by a certified Ichthyologist and has successfully kept and bred a wide variety of fish for a huge number of years(47+) with minimal problems doing what I have done for all these many years. There must be a reason why this happens wouldn't you think?
Class dismissed?
I don't use charcoal so wouldn't that change this?
And as for a water conditioner and minerals: I have a 50 gallon trash can that all my clean new water goes to after water changes then I add the conditioner and minerals to that and it sits for 4 weeks there before going into my tank. I have an air hose that runs to the bottom of it. So wouldn't that change things that your saying aswell?
I also use that water for top offs witch is a little more then a gallon of water every 3 days. So some minerals are being put back in before my 4 week water change
Sorry I've been doing this for a long time and have had a lot of thoughts over the years on why and how I do things. But I can say one thing I should have joined a forum a long time ago to understand more.
I used the charcoal example because when we had this discussion, carbon wasn't being used. Both charcoal and carbon act as a filter/ purifier so except for some certain exceptions, it's not a bad thing to use.
Topping off from evaporation: There are certain minerals that don't evaporate when the water does. Salt, (NaCl) is one of them. So as your water evaporates, the salt level increases allbeit slightly in a freshwater tank. When you add water for evaporation, you are adding some more salt to your water through the chemicals you are using to dechlorinate/ dechlorimine the water. Once again, this change may very well be insignificant to the overall volume of water and the fish, depending on the type, may show no ill effects of this change.
Another thing to remember is that your system is a living breathing system. Your bacteria beds are constantly growing and shrinking depending on the bioload. Removing larger volumes of water also can create drastic changes in this area too. Say you have just inadvertently overfed your tank and there are pockets of uneaten foods that your bacteria bed is growing to adjust to the ammonia load. You may or may not see this change in an ammonia reading. Now say that bed has blossomed and you do a large water change so that the ammonia level has now decreased drastically and you are now starving all those new bacteria that were produced to reduce the ammonia load. What do they do? They die off to a manageable level once again thereby causing a slight rise in the ammonia level and the cycle goes on. I used excess food in this example but a dead fish as well as other natural occurances can be substituted for the food. The bottom line is that there are changes that you are not always aware of that are occuring in your tank that larger water changes do effect. How much it effects the fish in the system varies from specie to specie.
In all honesty, I prepare the water I am going to use for a water change the day before I change it. Right now I am on well water so I don't add anything to it, just salt. When I had my hatchery, I had a Culligan carbon filter that removed the chlorine/ chlorimine from the tap water and we used that water straight from the hose. No other pre-prepping required. When I had my wholesale house, we used a Culligan filter with a PH adjuster and used the tap water straight from the filter to do water changes. (The PH adjuster was because we were importing a lot of fish from S. America and did a slow change to our higher PH water here in FL.) Once again, smaller changes more frequently enabled these fish to adapt better to the changes.
And that's really the bottom line. The smaller the changes, the easier it is for the fish to adjust to the changes no matter what they are. I know everybody has different experiences with their tanks and I am usually a proponant of "If it ain't broke, don't fix it!" except when it comes to water changes. In a saltwater tank, there are natural items that can be grown in the tank and consumed by the fish that replace the needs for water changes. What I have found is that fish kept this way over long periods of time, do not adapt well once moved to a new system. In my last move, I gave my fish to my friend's store to hold while I made my move (some 200 miles away.) I had had the three fish he was holding for a minimum of 8 years ( the longest being 13 years) so obviously, whatever I was doing must have been right. You'd think so wouldn't you? None of my fish lasted more than a week at the store. I supervised EVERYTHING so I know that everything with the change was done correctly yet they still didn't survive. In my freshwater tanks, I changed the water all the time. Whether from habit or whatnot, I had no problems with them. So that's why I still say that doing smaller changes more frequently will have a better effect on the fish than larger changes less frequently.
Be assured that I take no offense to your questions. I am not a scientist (& I don't play one on TV ) so I can't give you all the scientific reasons why things happen. What I am is a guy who was trained by a certified Ichthyologist and has successfully kept and bred a wide variety of fish for a huge number of years(47+) with minimal problems doing what I have done for all these many years. There must be a reason why this happens wouldn't you think?
Class dismissed?