TwoTankAmin
Fish Connoisseur
Just as an FYI- I have done this for a nunber of years. We have two portable RO/DI units in the house. I use the water for fish but my brother uses it in humidfiers.
My water is basically soft and neutral. But I love Altum angels and the ones from the wild live in water that is sometimes lower than 6.0 pH/ When I got them from recent import, I had a tank for them at 4.2 pH and between 20 and 30 ppm TDS. Altering ones parameters downward is much harder to do than raising them.
I should also say that what I do is the most economical way of doing this. I use almond leaves and alder cones as well as rooibos tea. The latter does nothing to soften the water or to lower the pH. It does do other good things including staining the water.
The first thing is that one cannot rely on hobby test kits to manage this process. I have a couple of hand held TDS neters and then a continuous digital monitor on the tank which gives real time readings for conductivity.TDS, temp in C or F and pH. The pH part needs to recalibrated about ever two months of so, I have the needed reagents for doing this. Here is the unit we use (I paid a bit less years ago)
https://www.amazon.com/dp/B0081K32B0/?tag=ff0d01-20
There is an important consideration relative to cycling when one is working with lowering pH into the acid range and that is the bacteria which keep our tanks cycled. They work best when the pH is in the 7.0 and above range. This is because they mostly prefer ammonia as NH3. However, when ammonia is in water it goes into two forms. Most of it becomes ammonium, NH4. This is way less toxic to life (but not safe either over time). As one moves towards a pH of 6.0 almost all of the ammonia in water will be in the form of NH4. Some bacteria must have NH4 to function and some is able to use NH4. but they do so less efficiently than they can process NH3. A lot of the good bacteria in tanks can adapt to an acid pH. But this take a bit of time.
The problems in a tank with acid water begin when the pH is allowed to drift upward. It has a tendency to do this over time and the solution is the same here as in a more normal tank--> water changes. However, when one is lowering their parameters one has to be managing a number of factors. Most of us mix tap and RO or RO/DI. This tends to work against the lowered parameters over time.
The two most important issues with artificially creating lowered paramters is determining the right chemistry needed to and then what the chemistry of all the water one is using and mixing is. It is not possible to just change a single of the major parameters an not have it effect anything else. Change the temp, and that changes the balance between NH3 and NH4. Change the pH and can have an effect of fish, plants and inverts as well as ammonia forms.
Between weekly water changes the pH and TDS tend to drift upwards. How much can vary. So I batch my changing water in a can next to the tank and I move the probes from the tank to the can so I can batch the new water to modifiy the tank parameters back to their target levels: pH 6.0, TDS between 50 and 60 ppm and temp at about 84F. I often must use bit of muriatic acid to adjust the pH downward. The addition of the acid will also raise the TDS.
Doing this stuff is neither simple nor easy. For a basic lesson in water chemistry etc I suggest one start by reading here:
F I N S : T h e F i s h I n f o r m a t i o n S e r v i c e
then click on Your First Aquarium and read the both sub-sections under
https://fins.actwin.com/mirror/begin-chem.html
Juat as an FYI- I only use abput 12 gallons a week of RO/DI. at 52 weeks a years this works out to 624 gallons. At just $1/gallon I can buy two 75 gpd RO/DI units like the ones we have. When my bro is running the humidifiers in winter he uses about 3 gal./day over about 130 days or so. That is another $390/year. So we could be spending about $1,000 every year or the roughly $500 we spend to buy our two units and then another maybe 25/year for calinration solutions and the need to replace the pH probe every 5 years or so (about $70).
Finally, I have the angels in a 55 gal. tank which is smaller than I would want ideally, but there are only 5 angels in it and Altums work best in groups. Since these are one of the most difficult fish to spawn in captivity, I have no worries on that front as I doubt I could succeed in spawning wild Altums if I worked at it for decades.
p.s. I otper for an RO/DI unit because it produces almost 100% pure water. When all the components are new my TDS reads 0 from the unit. When the deionizing resin is filled and no longer helping, the TDS will be more like 10 ppm. The DI unit removes ions. This would include nitrate for example.
My water is basically soft and neutral. But I love Altum angels and the ones from the wild live in water that is sometimes lower than 6.0 pH/ When I got them from recent import, I had a tank for them at 4.2 pH and between 20 and 30 ppm TDS. Altering ones parameters downward is much harder to do than raising them.
I should also say that what I do is the most economical way of doing this. I use almond leaves and alder cones as well as rooibos tea. The latter does nothing to soften the water or to lower the pH. It does do other good things including staining the water.
The first thing is that one cannot rely on hobby test kits to manage this process. I have a couple of hand held TDS neters and then a continuous digital monitor on the tank which gives real time readings for conductivity.TDS, temp in C or F and pH. The pH part needs to recalibrated about ever two months of so, I have the needed reagents for doing this. Here is the unit we use (I paid a bit less years ago)
https://www.amazon.com/dp/B0081K32B0/?tag=ff0d01-20
There is an important consideration relative to cycling when one is working with lowering pH into the acid range and that is the bacteria which keep our tanks cycled. They work best when the pH is in the 7.0 and above range. This is because they mostly prefer ammonia as NH3. However, when ammonia is in water it goes into two forms. Most of it becomes ammonium, NH4. This is way less toxic to life (but not safe either over time). As one moves towards a pH of 6.0 almost all of the ammonia in water will be in the form of NH4. Some bacteria must have NH4 to function and some is able to use NH4. but they do so less efficiently than they can process NH3. A lot of the good bacteria in tanks can adapt to an acid pH. But this take a bit of time.
The problems in a tank with acid water begin when the pH is allowed to drift upward. It has a tendency to do this over time and the solution is the same here as in a more normal tank--> water changes. However, when one is lowering their parameters one has to be managing a number of factors. Most of us mix tap and RO or RO/DI. This tends to work against the lowered parameters over time.
The two most important issues with artificially creating lowered paramters is determining the right chemistry needed to and then what the chemistry of all the water one is using and mixing is. It is not possible to just change a single of the major parameters an not have it effect anything else. Change the temp, and that changes the balance between NH3 and NH4. Change the pH and can have an effect of fish, plants and inverts as well as ammonia forms.
Between weekly water changes the pH and TDS tend to drift upwards. How much can vary. So I batch my changing water in a can next to the tank and I move the probes from the tank to the can so I can batch the new water to modifiy the tank parameters back to their target levels: pH 6.0, TDS between 50 and 60 ppm and temp at about 84F. I often must use bit of muriatic acid to adjust the pH downward. The addition of the acid will also raise the TDS.
Doing this stuff is neither simple nor easy. For a basic lesson in water chemistry etc I suggest one start by reading here:
F I N S : T h e F i s h I n f o r m a t i o n S e r v i c e
then click on Your First Aquarium and read the both sub-sections under
https://fins.actwin.com/mirror/begin-chem.html
Juat as an FYI- I only use abput 12 gallons a week of RO/DI. at 52 weeks a years this works out to 624 gallons. At just $1/gallon I can buy two 75 gpd RO/DI units like the ones we have. When my bro is running the humidifiers in winter he uses about 3 gal./day over about 130 days or so. That is another $390/year. So we could be spending about $1,000 every year or the roughly $500 we spend to buy our two units and then another maybe 25/year for calinration solutions and the need to replace the pH probe every 5 years or so (about $70).
Finally, I have the angels in a 55 gal. tank which is smaller than I would want ideally, but there are only 5 angels in it and Altums work best in groups. Since these are one of the most difficult fish to spawn in captivity, I have no worries on that front as I doubt I could succeed in spawning wild Altums if I worked at it for decades.
p.s. I otper for an RO/DI unit because it produces almost 100% pure water. When all the components are new my TDS reads 0 from the unit. When the deionizing resin is filled and no longer helping, the TDS will be more like 10 ppm. The DI unit removes ions. This would include nitrate for example.
Ammonia as NH3 has a neutral charge but when it turns to ammonium NH4,
Both nitrite and nitrate are ions which would be removed from any water containing these things which is processed through a DI unit.
