When I first entered the hobby I was taught the same things we all have heard many times over. "Fish are adaptable", "it is more important to keep a stable chemistry" or "it is all about the acclimation procedure" So after spending many, many hours researching equipment and fish I setup my first aquarium. A 75 gallon Perfecto with lovely brown fake wood trim. Bought some "hardy" fish to cycle it with, got through my cycle and started adding fish. Some would die during the acclimation process or a few days later but many would survive and do well in my aquariums. I knew they were doing well because they were swimming around and eating food. During this time my wife and kids also had aquariums filled with a variety of community fish. We learned that some fish were hardier than others. The hardy fish seemed indestructible and the sensitive fish would sometimes die inexplicably during small water changes or for no obvious reasons at all.
After a little bit of time keeping fish I became interested in Tanganyikan cichlids of various types. I quickly learned that they were all super hardy fish. I almost never lost fish during acclimation. Even fish that were widely known as being difficult such as Tropheus I found very easy to keep. 75% water changes became the norm for me and there were no issues with these hardy fish known as cichlids. My wifes interests had moved to mbuna and these fish exhibited the same qualities. At this point I thought cichlids were the best fish ever. So much easier to keep than general community fish. Over time, my interests shifted again and I began to be interested in South American cichlids. Mysteriously, these fish began to display the same types of problems as I had with the community fish I had kept earlier on. I would have losses during or shortly after acclimation, mysterious deaths at random times. Especially when dealing with smaller/younger cichlids.
At this point, I began to realize that the fish I thought were "sensitive" or "fragile" all came from the softer waters of South America, Asia or West Africa and the fish I thought were "hardy" all came from the harder waters of Central America or the African rift lakes. My water tap water is hard and alkaline. Last time I tested my tap water it was pH 7.8, KH 12, GH 20+. I had enough anecdotal evidence to consider that maybe hardness does matter after all. So I decided to try setting up an RODI system and started keeping my fish that originated from softer waters in......softer water. Not surprisingly for some of you, this had the desired effect of turning almost all my fish into "hardy" fish. I stopped losing SA cichlids during acclimation, I was able to stop worrying about every water change with those fish. Even small tetras became easier to deal with. What was more surprising to me was the behavioral changes. Many of my fish became more active and started displaying different behaviors. I started thinking that maybe what I had been taught about acclimation and water conditions was not quite right.
Lately, I have been thinking about what was really contributing to my success and failure and how to measure it. Even though I had been thinking about "soft" water and "hard" water I think that dGH can't really be the right measure. I believe this because for much of my time in the hobby my water has been passing through a household water softener. All the water I have has 0 dGH. While my hard water fish seemed to thrive in this water, my soft water fish did not. Because of this, I believe that the primary thing that I can measure is Total Dissolved Solids(TDS).
Here are some of things I have come to believe from the information referenced above and my time as an aquarist since.
TDS is king:
Take a look at this informative post written by Caliban07 for details of why TDS matters. Please note, I am not saying that other factors such as dGH and pH do not matter. I simply believe they don't matter as much as TDS. Moreover, in naturally occurring water I suspect that dGH and TDS values would be fairly well correlated although I have never tried to collect data to validate this belief. I feel like this point is especially important because I see a lot of posts that start out with "I have pH 7.8 water will I be able to keep <insert random fish here>?" In reality, I am always trying to figure out how hard their water is.
Fish are adaptable:
Fish are amazingly adaptable creatures but I think that we sometimes overstate how adaptable they are because we really want to keep them in our aquaria. While I do not believe that you have to provide the exact correct chemistry I also don't believe that you can move them drastically from one end of the spectrum to the other. What makes this difficult is that many people have water that is either very hard or very soft. Moreover, most tropical fish come from water that is either very hard or very soft. This means that most of the time the water is fairly close to natural conditions or very far away.
Surviving is not the same as thriving:
As far as I know, there is no meter or system of measure which describes the level of appropriateness of the environment for the fish. I am not sure why, but the two common ones used seem to that the fish is alive and exhibiting spawning behavior. While being "not dead" and reproducing are both good things I struggle to believe that they are indicators of a thriving organism. Unfortunately, I don't have anything that is universally better. What I do have is my own observations as I moved fish from one environment to another and the related changes in mortality rates and behavioral changes.
There are fragile fish:
While I firmly believe that fragile fish exist, there are not as many as it sometimes seems. Most of the truly fragile fish I have come across are due to breeding practices such as being line bred poorly or being pumped with hormones to improve color. Also, poor care and/or shipment of the fish at a young age are common problems that cause apparent fragility.
Here are some of the counter arguments or common sayings I see on a fairly regular basis and my thoughts on them:
It is more important to keep a steady water chemistry than have a highly specific chemistry:
I certainly agree that it is better, relatively speaking, to have a steady water chemistry than one that is bouncing around. However, that does not infer that you can keep any fish in any water as long as it is stable. That being said, I completely agree that dumping all sorts of chemicals into a tank in order to alter water chemistry is fraught with peril. Especially if you are trying to turn hard, alkaline water into soft, acidic water. It is possible to alter water chemistry and still provide stable conditions. It may take some effort or money depending on what you need to alter.
Captive bred fish no longer need the parameters of their wild bred brethren:
It seems hard to believe that a few generations of captive breeding can erase centuries of evolution. There is no doubt that fish evolve rapidly but that seems a little too rapid to be reasonable. Even when dealing with soft water fish that were bred in hard water they seem to appreciate being acclimated back to softer, more acidic conditions. Now, the exception to this would be some of the species which have been captive bred for 100's of generations. Examples of this would be the domestic angelfish or the domestic platy. This actually isn't the case for most fish though. Only long-time heavily line-bred fish typically get bred for this many generations. With most other fish even the tank raised variety are not that many generations removed from wild stock.
Most fish are captive bred in hard water anyway:
It is true that many of the fish farms in Florida have hard water. However, it is not true that most of the captive bred fish come from Florida. On top of that, more fish are wild caught than most people seem to think. I see wild stock of common fish on a pretty regular basis. Also, many of the species we keep either have not been captive bred or are not regularly bred in captivity.
Your local store probably has the same water you do so as long as your buying from a local source everything will be good:
Easily the most baffling of the opinions I see and one of the most common. Speaking logically, how does a few days or weeks in your local store magically cause fish to evolve to handle different water? Once again, the only thing you can really infer from this is that the fish are not dead. While being alive is certainly something I look for in fish I am buying it doesn't mean they are in peak health or that they have not been weakened by the forced acclimation. The reality is that many fish are able to adapt to temporarily survive in different conditions. However, that does not translate to them thriving in those conditions for their whole life.
I have kept <insert fish here> in my water for years they are thriving:
This statement is sometimes followed by the fact that they saw spawning behavior so they must be ideal conditions. My question will always be the same, how do you know they are thriving? Did you also have a tank in the appropriate water for the fish where you compared their behavior and life spans? If not, how did you determine that there was no difference?
For those people that were actually willing to read to this point in this unexpectedly long post I hope that even if you don't agree with me I have given you some things to think about. If this is making sense to you and you are wondering what you can do about it, I think there are really two solutions to the problem.
The easiest one is simply to keep fish that come from conditions that are not too far off from your tap water. The other solution is to alter the chemistry to something that is closer to what the fish need. The exact method for doing this will vary greatly depending on what kind of water you are starting from and where you are trying to get to but it can always be done. In some cases, it is easier or less expensive than others. In general, it is a lot easier to make water harder and more alkaline than it is to make it softer and more acidic.
Is everything above accurate? Probably not. For one thing it is mostly based on anecdotal evidence. Moreover, I have no experience taking hard water fish and keeping them in soft water. Only the opposite. Therefor, I am simply assuming that the effects are similar. Lastly, if there is one thing I have learned about this hobby it is that few things are absolute and different species of fishes are unique in many ways.
I do, however, know that I have been a much more successful aquarist since I started keeping fish in waters more appropriate to their origin.
After a little bit of time keeping fish I became interested in Tanganyikan cichlids of various types. I quickly learned that they were all super hardy fish. I almost never lost fish during acclimation. Even fish that were widely known as being difficult such as Tropheus I found very easy to keep. 75% water changes became the norm for me and there were no issues with these hardy fish known as cichlids. My wifes interests had moved to mbuna and these fish exhibited the same qualities. At this point I thought cichlids were the best fish ever. So much easier to keep than general community fish. Over time, my interests shifted again and I began to be interested in South American cichlids. Mysteriously, these fish began to display the same types of problems as I had with the community fish I had kept earlier on. I would have losses during or shortly after acclimation, mysterious deaths at random times. Especially when dealing with smaller/younger cichlids.
At this point, I began to realize that the fish I thought were "sensitive" or "fragile" all came from the softer waters of South America, Asia or West Africa and the fish I thought were "hardy" all came from the harder waters of Central America or the African rift lakes. My water tap water is hard and alkaline. Last time I tested my tap water it was pH 7.8, KH 12, GH 20+. I had enough anecdotal evidence to consider that maybe hardness does matter after all. So I decided to try setting up an RODI system and started keeping my fish that originated from softer waters in......softer water. Not surprisingly for some of you, this had the desired effect of turning almost all my fish into "hardy" fish. I stopped losing SA cichlids during acclimation, I was able to stop worrying about every water change with those fish. Even small tetras became easier to deal with. What was more surprising to me was the behavioral changes. Many of my fish became more active and started displaying different behaviors. I started thinking that maybe what I had been taught about acclimation and water conditions was not quite right.
Lately, I have been thinking about what was really contributing to my success and failure and how to measure it. Even though I had been thinking about "soft" water and "hard" water I think that dGH can't really be the right measure. I believe this because for much of my time in the hobby my water has been passing through a household water softener. All the water I have has 0 dGH. While my hard water fish seemed to thrive in this water, my soft water fish did not. Because of this, I believe that the primary thing that I can measure is Total Dissolved Solids(TDS).
Here are some of things I have come to believe from the information referenced above and my time as an aquarist since.
TDS is king:
Take a look at this informative post written by Caliban07 for details of why TDS matters. Please note, I am not saying that other factors such as dGH and pH do not matter. I simply believe they don't matter as much as TDS. Moreover, in naturally occurring water I suspect that dGH and TDS values would be fairly well correlated although I have never tried to collect data to validate this belief. I feel like this point is especially important because I see a lot of posts that start out with "I have pH 7.8 water will I be able to keep <insert random fish here>?" In reality, I am always trying to figure out how hard their water is.
Fish are adaptable:
Fish are amazingly adaptable creatures but I think that we sometimes overstate how adaptable they are because we really want to keep them in our aquaria. While I do not believe that you have to provide the exact correct chemistry I also don't believe that you can move them drastically from one end of the spectrum to the other. What makes this difficult is that many people have water that is either very hard or very soft. Moreover, most tropical fish come from water that is either very hard or very soft. This means that most of the time the water is fairly close to natural conditions or very far away.
Surviving is not the same as thriving:
As far as I know, there is no meter or system of measure which describes the level of appropriateness of the environment for the fish. I am not sure why, but the two common ones used seem to that the fish is alive and exhibiting spawning behavior. While being "not dead" and reproducing are both good things I struggle to believe that they are indicators of a thriving organism. Unfortunately, I don't have anything that is universally better. What I do have is my own observations as I moved fish from one environment to another and the related changes in mortality rates and behavioral changes.
There are fragile fish:
While I firmly believe that fragile fish exist, there are not as many as it sometimes seems. Most of the truly fragile fish I have come across are due to breeding practices such as being line bred poorly or being pumped with hormones to improve color. Also, poor care and/or shipment of the fish at a young age are common problems that cause apparent fragility.
Here are some of the counter arguments or common sayings I see on a fairly regular basis and my thoughts on them:
It is more important to keep a steady water chemistry than have a highly specific chemistry:
I certainly agree that it is better, relatively speaking, to have a steady water chemistry than one that is bouncing around. However, that does not infer that you can keep any fish in any water as long as it is stable. That being said, I completely agree that dumping all sorts of chemicals into a tank in order to alter water chemistry is fraught with peril. Especially if you are trying to turn hard, alkaline water into soft, acidic water. It is possible to alter water chemistry and still provide stable conditions. It may take some effort or money depending on what you need to alter.
Captive bred fish no longer need the parameters of their wild bred brethren:
It seems hard to believe that a few generations of captive breeding can erase centuries of evolution. There is no doubt that fish evolve rapidly but that seems a little too rapid to be reasonable. Even when dealing with soft water fish that were bred in hard water they seem to appreciate being acclimated back to softer, more acidic conditions. Now, the exception to this would be some of the species which have been captive bred for 100's of generations. Examples of this would be the domestic angelfish or the domestic platy. This actually isn't the case for most fish though. Only long-time heavily line-bred fish typically get bred for this many generations. With most other fish even the tank raised variety are not that many generations removed from wild stock.
Most fish are captive bred in hard water anyway:
It is true that many of the fish farms in Florida have hard water. However, it is not true that most of the captive bred fish come from Florida. On top of that, more fish are wild caught than most people seem to think. I see wild stock of common fish on a pretty regular basis. Also, many of the species we keep either have not been captive bred or are not regularly bred in captivity.
Your local store probably has the same water you do so as long as your buying from a local source everything will be good:
Easily the most baffling of the opinions I see and one of the most common. Speaking logically, how does a few days or weeks in your local store magically cause fish to evolve to handle different water? Once again, the only thing you can really infer from this is that the fish are not dead. While being alive is certainly something I look for in fish I am buying it doesn't mean they are in peak health or that they have not been weakened by the forced acclimation. The reality is that many fish are able to adapt to temporarily survive in different conditions. However, that does not translate to them thriving in those conditions for their whole life.
I have kept <insert fish here> in my water for years they are thriving:
This statement is sometimes followed by the fact that they saw spawning behavior so they must be ideal conditions. My question will always be the same, how do you know they are thriving? Did you also have a tank in the appropriate water for the fish where you compared their behavior and life spans? If not, how did you determine that there was no difference?
For those people that were actually willing to read to this point in this unexpectedly long post I hope that even if you don't agree with me I have given you some things to think about. If this is making sense to you and you are wondering what you can do about it, I think there are really two solutions to the problem.
The easiest one is simply to keep fish that come from conditions that are not too far off from your tap water. The other solution is to alter the chemistry to something that is closer to what the fish need. The exact method for doing this will vary greatly depending on what kind of water you are starting from and where you are trying to get to but it can always be done. In some cases, it is easier or less expensive than others. In general, it is a lot easier to make water harder and more alkaline than it is to make it softer and more acidic.
Is everything above accurate? Probably not. For one thing it is mostly based on anecdotal evidence. Moreover, I have no experience taking hard water fish and keeping them in soft water. Only the opposite. Therefor, I am simply assuming that the effects are similar. Lastly, if there is one thing I have learned about this hobby it is that few things are absolute and different species of fishes are unique in many ways.
I do, however, know that I have been a much more successful aquarist since I started keeping fish in waters more appropriate to their origin.
Last edited:
.
but I have to wonder, since no specifics were given as to the nitrate levels, is it possible that the fish that were dying were in fact being killed off by the fish that were spawning? That IS typical cichlid behavior as I know it. 
