Switching the co2
back on. I canít grow the plantís I have because unfortunately my water is just too soft and as a result there is no KH
to appease the carbonate users.
I tried adding dolomite but itís not very soluble, resulting in milky water for a day. Hopefully the lower pH will help it dissolve better and I can use it as a reliable, natural source of calcium, magnesium and KH
going forward. It does produce a response but doesnít seem to last very long before you need to re-dose. All you end up with is tons of Calcium and salt precipitation on the sides of the glass, where you can tell thereís way too much Ca
Secondly, I tried potassium bicarbonate which adds insane amounts of potassium. This had adverse effects on both shrimp and snails too. I wasnít performing water changes at the time so itís possible the rapid shift in pH due to KH
buffering made underlying ammonium toxic. I never tested for ammonia at the time because I had ran out of reagent and doing water changes immediately was imperative. Though after an 80% water change I repeated the test (gulp!) and the same thing happened. Iím doubtful there would have been enough ammonium in the tank after an 80% water change to have have the exact same response from fish, snails and shrimp but it is possible. My main hypothesis is that with soft water with very little calcium, sodium, sulphates, magnesium, carbonates and chloride and the solubility of potassium this resulted in a rapid increase in ions causing osmoregulatory distress. I believe this also because ALL my crypts melted which is a classic sign of ion imbalance in crypts i.e they donít like the new water so they melt and regrow.
I tried changing 10l of water every day to provide a constant and stable level of KH
from my tap even though it is minuscule. It didnít work and fish got sick.
Lastly, I tried adding a more natural, fully dissolved hard water composition. Bottled spring water with lots of bicarbonate. Again, just like dolomite, the original response was good but it was short lived. Some plants are still showing signs of growth as a result but I donít believe that is due to the bicarbonate alone.
The duckweed, had not been proliferating this whole time which would suggest a nutrient issue because they donít care about co2
, but Iíd been adding EI levels of macros and some iron for micros so nutrients should have been aplenty. It is said that amazon frogbit is a better indicator when using the leaf colour chart in softer water as Duckweed prefers harder water so this could become the reason the duckweed was lagging. Since adding the spring water the duckweed has grown somewhat but hasnít gone wild. This may suggest that there is very intense competition within the tank for carbonates and not just from plants. Spring water is expensive though so It wasnít a sustainable option. Especially when water is evaporating so quickly in the drier, colder months when the heating is on full.
Therefore Iíve admitted defeat. I need to either use co2
or change out the plants for those that donít rely heavily on carbonates but uprooting long time submerged crypts is risky.
Iím still doing no water changes at this point. Just top ups with rain or RO
. I worry about the many Malaysian trumpet snails now with the co2
making the water more acidic. Hopefully the decaying of old leaves that is inevitable now the co2
content is going to rise will provide them with a decent amount of food and calcium for their shells.
Iím out all day today and so co2
goes on tomorrow where I can be home all day to monitor the concentration.
I believe the tank is nutrient dense now and simply switching co2
on will send the plants in to overdrive. Iím also expecting zero algae blooms due to the stability of the biofilter.
Watch this space for more updates