Can I make blackwater using my tap water?

[Mike Wise]

It's amazing the different pollutants that are in the air and deposited on your roof. I would recommend that the next time it rains wait about 15 minutes before collecting water. That should be enough time to wash off the roof.

 

[dw1305]

Hi all,

I don't think there should be anything harmful though?

It should be fine. Just strain the larger debris out.

So I collected a tub of rainwater, it is pH 6 and TDS 12

The pH isn't really measurable (just because of the low conductivity of the water), but "TDS" 12 ppm is absolutely perfect.

cheers Darrel

 

[Mazan]

OK maybe I will not use it this time then, to be on the safe side. Also as it was raining very hard quite a lot of stuff ran off the roof. We live out in the country but as you say, you never know what rain water picks up on the way. With the peat water I am only changing about 40l (10 gallons) at a time, the tank is 240l (about 63 gallons), though the actual volume is less due to substrate and branches etc.

 

[Ben Rhau]

At that rate, It would take 10 - 15 water changes to replace 90% of your water. Since there is such small difference between your tank water and the peat water, I think you can either do larger water changes, or daily 20% changes for 8 or 9 days straight (or until you see a difference).

I realize you may be limited by how much peat water you can make at a time.

Cheers

 

[Mazan]

Yes, I realize it will take a while, and I haven't been able to do water changes every day, (mostly due to long power cuts, when the power is off we board up the tanks to conserve heat, and when its on there are always lots of other things that need doing). And my peat container is not very big, but anyway I will keep trying...

 

[Mazan]

I haven't updated for a while but the tank is still staying at pH about 6.5. Until a couple days ago I had only done periodic small water changes with the peat water, but we managed to set up a rain collecting system that does not involve run off from the roof, just in case, so I have recently done a couple of larger water changes with rain water (when standing a while it has pH 5.5 same as the peat water). This morning I tested the pH first thing before the lights were on and it was around 5.5 or 6. But within an hour of the lights on it had gone back to 6.5. Could the plants make that much difference so quickly? Are the floating plants using or blocking the top of the tank not letting in any CO2? Would extra aeration help? Is it even important? The TDS of rain water is 10, in the tank is still at 26. KH is 0 or 1? (goes yellow on the first drop, never turns green or blue). I have almond and other leaves and wood in the tank, people always worry about pH crashes with low KH but it doesn't seem to happen in my case!

Anyway the male pike cichlid does get excited and display to the female especially after a water. change, and follows her around, usually I see them together, the female is looking quite fat but doesn't usually respond much to the displays so far...

 

[dw1305]

.... This morning I tested the pH first thing before the lights were on and it was around 5.5 or 6. But within an hour of the lights on it had gone back to 6.5. Could the plants make that much difference so quickly?

They can, in very soft water a small decrease in CO2 levels will raise pH levels.

Are the floating plants using or blocking the top of the tank not letting in any CO2? Would extra aeration help? Is it even important?

Probably not.

The TDS of rain water is 10, in the tank is still at 26. KH is 0 or 1? (goes yellow on the first drop, never turns green or blue). I have almond and other leaves and wood in the tank, people always worry about pH crashes with low KH but it doesn't seem to happen in my case!

Just ignore what you read about dKH, pH or buffering, it is written by people who don't know what they are talking about.

Anyway the male pike cichlid does get excited and display to the female especially after a water. change, and follows her around, usually I see them together, the female is looking quite fat but doesn't usually respond much to the displays so far...

Perfect.

Cheers Darrel

 

[Ben Rhau]

I don't think there's enough of a difference between the source water and your tank water to see a big change in pH. My guess is that the leaves and wood add some buffering capacity.

people always worry about pH crashes with low KH but it doesn't seem to happen in my case!

I've posted about this several times. I don't think it's possible.

Anyway the male pike cichlid does get excited and display to the female especially after a water. change, and follows her around, usually I see them together, the female is looking quite fat but doesn't usually respond much to the displays so far...

Great, maybe the pH itself doesn't matter so much?