My current water pH is maintain at 7.8 is it too high? Should i lower the pH?
In this pH level will it lead to iron deficiency?
I live in Malaysia and i only can find EDTA Chelated Iron but have hard time to find chelated Iron Fe-DTPA and EDDHA. In such cases should i use EDTA to treat my iron deficiency? Should i lower my pH to dose in EDTA since is only efficient in lower pH?
As for potassium deficiency; I have difficulty to find potassium carbonate as well. Just wonder can i use potassium nitrate or Mono Potassium Phosphate (MKP) as alternative?
In case it makes a difference, you're looking for potassium bi-carbonate. But that's mostly for pH adjustment. You could also use potassium hydroxide for raising pH and adding potassium, which I know you can make by filtering water through wood ash (like in soap making).
Are you using well water?
Thank you Alex for your reply; as you mentioned filtering water through wood ash; is it for rising pH or adding potassium?
Can i use coconut husk fiber as alternative? I read some used Catappa leave (Indian almond) to lower water pH.
Back to my question; can you help to enlighten me on my doubt. Thanks again cheers
pH should be max 7.0 for plants and fish preferably 6.5. Potassium Carbonate will raise your pH.
I would use potassium Phosphate as my first choice
Careful with the iron. It will darken your water.
I would consider starting by testing the general & carbonate hardness of your water, both the source & your current tank water. If you live in an area with water that is hard (ie high in minerals, usually Calcium or Magnesium but it can be others) your pH will usually fall on the high side of neutral (7) like yours does. Hard water makes it notoriously hard to regulate pH either way. The hardness of your tank water will increase every time you top it up without a water change as only the water will evaporate not the minerals. Aquarists will often go so far as to put in a reverse osmosis water filter to eliminate the high GH or KH problems with local water. If your source water is good on hardness values (50-100 ppms) check the pH after it has set out in a bowl for 24 hrs. It can be anywhere from 6.5 to 7.5 & be acceptable for for fish but fish species will vary in their comfort ranges & it depends on what you want to stock. Tilapia don't really care too much as long as you don't make any rapid changes, trout can be really picky. If the hardness & pH are only high in your tank water then start looking for the source of that in your tank or your grow media. Drift wood or Indian Almond leaves can lower your pH somewhat but only very slightly in hard water. Lye, limestone, any Carbonate compound or sea shells will increase your pH. Knee jerk additions of this chemical or that chemical can cause huge swings in the balance that you are trying to achieve to the detriment of both your fish & your plants.
As far as your potassium deficiency, why not add worms to your GB? Their castings are a natural source.