<a href=showthread.php?s=&postid=13753279#post13753279 target=_blank>Originally posted</a> by hndakd
I thought the same thing with the straw idea.
By depressed you mean the excess co2 in my house is making the ph drop right? Its a little cold to be opening doors and windows here so i guess that isnt really an option.
Yes, by “depressed†I mean “low†and mean to say that the CO2 in your house is likely elevated (the norm) and is keeping tank pH low. Agreed, opening doors/windows is only a good option when the weather is mild outdoors.
<a href=showthread.php?s=&postid=13753279#post13753279 target=_blank>Originally posted</a> by hndakd
from what i have read about kalk it seems like it would do the trick. What i have read though says that it should only be used to keep levels stable not to supplement them.
Kalkwasser provides calcium and alkalinity in the same ratio that they are used when CaCO3 is produced. The calcifying organisms in the tank are produce mostly CaCO3 (as well as smaller amounts of MgCO3) to produce their skeletons. The effects of the kalk on calcium and alkalinity depends on the demand in the tank. If you add kalkwasser to some an aquarium you will raise both calcium and alkalinity immediately after dosing (the alkalinity is added as OH- but combines with CO2 and HCO3- already present in the water to give HCO3- and CO3=).
1) If there are no calcifying organisms present (assuming no abiotic precipitation) both calcium and alkalinity will remain elevated by the amount that you added.
2) If the calcifying organisms are calcifying at the same rate that you are adding calcium and alkalinity with kalkwasser then both will remain the same over time; you will thereby “maintain†calcium and alkalinity.
3) If the calcifying organisms are removing calcium and alkalinity faster than you can replace them with kalkwasser then both calcium concentration and alkalinity will drop over time.
Whether calcium and alkalinity rise, stay the same, or drop when using kalkwasser depends on the rate of addition (= how much kalkwasser is added each day) and how fast calcium and alkalinity are used up in the tank.
Kalkwasser will add calcium and alkalinity of 20 ppm calcium for every 2.8 dKH = 1 meq/l alkalinity. So, if you increased alkalinity from ~7 dKH that you have now to ~9.8 dKH with kalkwasser you would raise calcium from ~400 ppm to ~420 ppm.
We can only add so much kalkwasser so fast though. When we add kalk we are reducing the amount of dissolved CO2 in the water (converted to HCO3- and CO3= with OH-) which raises the pH. As long as we add the kalk slowly the pH doesn’t rise too high because atmospheric CO2 dissolves into the water. That takes time though. If we add a lot of kalk at once (e.g., mix up a day’s worth in a cup and dump it in) the pH will spike very high and it may take hours to return to acceptable levels. Hence, we can only add kalkwasser so fast (dripwise is best). If we add more kalkwasser than we have evaporation the salinity will drop over time, which is not the goal.
<a href=showthread.php?s=&postid=13753279#post13753279 target=_blank>Originally posted</a> by hndakd
with that being said, the low alk and ph would then be affected where as the calcium would remain the same>>?
All will be increased by dosing kalkwasser. However, whether calcium and alkalinity increase over time, stay the same, or decrease depends on how much kalkwasser is added each day and what the demand for calcium and alkalinity is in the tank. The effect on pH is temporary. The pH is determined by the alkalinity and dissolved CO2. However, most aquaria require frequent or daily supplementation to make up for calcification, it is possible to keep some tanks constantly out of equilibrium with the atmosphere by dripping kalkwasser.
<a href=showthread.php?s=&postid=13753279#post13753279 target=_blank>Originally posted</a> by hndakd
There is a huge amount of info in these threads so i dont know if im just jumping to conclusions or im not getting it.
No worries: hopefully the above clarifies.
<a href=showthread.php?s=&postid=13753279#post13753279 target=_blank>Originally posted</a> by hndakd
can i just use my auto top off? I have a five gallon bucket that I put my rodi water in and it just tops off as necessary. If I use the bucket wont it get a "crust" in it.
You should be able to use your ATO. Yes you will get a crust of CaCO3 on the top of the water. It’s harmless but you probably will need to occasionally clean out the bucket. If it were me I’d mix up a saturated solution of kalk in the bucket (2 tsp per gallon), let it settle for several hours with the ATO off, then flip the ATO back on. Refill and clean as necessary.
cj
