Is My Kh Too Low?

[oldwhitewood]

Hey guys,

At the moment my KH is 2 and my ph about 6.5, do you think I should buffer the KH with bicarb of soda?

 

[George Farmer]

No.

There, that was easy!

KH 2 is fine in your tank Neil. You have low fish stock and I'm assuming you do decent water changes. These two factors will help ensure your pH doesn't crash.

My personal belief is that pH crashes with low KH are generally associated with poor maintenance i.e. allowing the nitrifying processes to build-up via lack of water changes and filter maintenance. The process of excessive nitrification causes acidic build-up that can eat away at KH. This is common in old-tanks where over time NO3 levels have built-up and the substrate has gone sour, also associated with UGFs.

Your fish and plants will prefer this soft water and pH 6.5 is just right too, and it matches the conditions of your substrate.

In summary do not worry.

 

[oldwhitewood]

Thanks mate, I normally do a big water change every week but I am just scared of ph/bacteria crash type of thing. It happened before in my old tank you see and it was horrible to watch.

 

[George Farmer]

Thanks mate, I normally do a big water change every week but I am just scared of ph/bacteria crash type of thing. It happened before in my old tank you see and it was horrible to watch.

What water change routine and fish load did you have when it crashed?

 

[oldwhitewood]

Fish load was minimal, I've never been big on keeping loads of fish. I'd missed a few water changes I must say but nothing major. I'd taken my filter apart to clean it but as usual I had to manually fill it up to get it going, it's one of those hydor external ones on my 125. Anyway I did this with tap water - which I had dechlorinated! I noticed when I started the filter a load of crap came out of the outlet, which seemed a bit weird but nothing unsual, as if I had disturbed it. Anyway I also increased the CO2 slightly, again nothing too drastic. I went out and when I got back later on that evening the fish were all swimming near the surface gasping for air. I immediately thought arrrah not oxygen so I moved the outlet to create surface agitation, at this point my amano shrimp started dying in front of my eyes, they'd swim to the surface to get air and then twitch sporadically in the water until sinking to the bottom dead. This seemed to be happening over the space of about a minute, then the fish started to peg it in the same way. I immediately did a really big water change to try and get some oxygen back into the water and left the outlet agitating the surface all night. The following morning about 70% of the tank inhabitants were dead, I spent a long time netting the dead fish and shrimp, very upsetting. I visited a few LFS and they all seemed to agree I'd destroyed the bacteria in my filter, I added some cycle and waited, things seemed to sort themselves out in a few days and my remaining hard as nails glowlight tetras were joined by some new buddies and some bleeding hearts. I'd never had any problems like that before in my years of fishkeeping, I reckon it must have been ph crash but I still don't understand fully why it happened. Anyway after that disaster I began using EI with the help of Richard from Aqua Essentials and the stuff I'd read on this forum and your journal too George - the tank flourished. It turned into the best aquascape and tank I'd done, I think this picture sums it up..........it's gone to pot now though as I've robbed a lot of the fern for my big tank and I'm going to replace it with a smaller tank etc. I can never maintain these things!

 

[iggy01]

Hey guys,

At the moment my KH is 2 and my ph about 6.5, do you think I should buffer the KH with bicarb of soda?

I noticed at the start of your journal a couple of weeks ago (nice tank by the way), you had 3 dKH. Why is it now down to 2 dKH? Has the KH of your tap water changed or is something in your tank eating into it?