Kh Khonfusion

  • We are currently upgrading MFK. thanks! -neo
hmm. completely opposite statements from different sources...who knows?

anyway, I think I have discovered where my carbonates went! I went home and talked to the wife and we were talking about it and she mentioned something the kiddos had been up to...

I took my son and daughter fishing a few days ago and they were playing in a puddle near the river. I asked what was up and they said there were 'things' in the water. I took a look and informed them the 'things' were mosquito larvae. For the rest of the day they were inspecting any water they could find for wrigglers. They asked why there werent any in the river itself, just in puddles. I said that the puddles didnt have fish and that the ones in the river all got eaten by fish. I know, I know, not entirely accurate but if you have kids then you know, a simple answer is usually the best one. They asked if fish liked to eat them and I said yeah, they love em.

well they took that information to heart. I have a 55 gal trash can outside that I have been soaking wood we've picked up and cocoanuts we've bought in. I've been busy and havent changed the water out for awhile. Unbeknownst to me at the time this trash can has a thriving population of mosquito larvae in it. The kiddos where scooping them out with a cup and dumping them into the aquariums, especially the new one. The water in this thing has gone beyond tea and is about as dark as black coffee. I poured some into a white 5 gallon bucket and couldnt see the bottom of the bucket lol. I have to think that them dumping this highly acidic water into the aquarium killed the Kh. Mystery unravelled I believe. I am assuming the water has 0 Kh and is very acidic, I couldnt get a test result I felt like was reliable because the water is already so discolored.

I gave the kids a fine mesh fishnet and told them to go nuts, but dont pour anymore of that water into the tanks.

The real upshot to this is that our tap water is too high in carbonates for the setup I am working on. 0 is of course too low, but now I can lower it in a controlled fashion. I've begun experimenting with this Kh lowering water, using known amouts of water and checking the Kh and Ph, so that all i have to do is keep the same ratio for larger amounts of water (the tank). It seems to take very little of the stuff to drop the Kh, so it dilutes and there is no noticable discoloration of the water. Also unlike putting peat in the filter, its a one-shot deal that wont slowly but continuously lower Kh and also discolor the water, and it doesnt need replacing every so often like peat, just get some of the magic water out of that can when I do WC. Its also more natural than the chemical Ph adjusters. Instead of dumping it, I put a lid on the can and I am really hoping I can turn this into a free way of reliably controlling the high Kh of my tap water.

Has anyone else ever used this method to adjust Kh instead of using peat? If it works, I really think this way could be superior to peat in some respects. I dont know what is in blackwater extract, but I think I am basically homemaking concentrated blackwater.
 
A change in CO2 concentration leads to a change in H2CO3 (carbonic acid) concentration which affects the pH. Also, planted aquaria naturally produce acidifying compounds (tannic acid, uric acid, as well as the humic acid already mentioned) that react with the carbonate buffers to produce more H2CO3.

When you have more CO2 in the water, more H2CO3 is produced, which dissociates into HCO3- (bicarbonate) and H+ (hydrogen) which is measured as a lower pH.

Your KH is being used up because you have something out of equilibrium - more frequent water changes are needed and you may need to add buffer periodically. Many planted aquariums do not require CO2 injection and most will do fine without, just at a slower total growth rate - how heavily is yours planted?

(I find "setups" risky IMHO as most fish can be acclimated to your water and when you start using complicated recipes, there is more room for fatal errors, and it is difficult or impossible to do rapid water changes if needed in an emergency situation).


Oh, my typing coincided with your last post which seems to explain some of your troubles!
 
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