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I'm considering setting up a system to harvest rainwater for fish tank use.
My tap water is pretty good but I do use a lot of it for the fish so considering alternatives.
After a moderate amount of online research and coming up with lots of advice on rainwater harvesting for toilet flushing or warmtering lawns, I'd welcome some advice from someone who has set up a rainwater harvesting system for fish tanks. What sort of system do you have? What do you use to store the water (I was thinking of an IBC) and do you use any filtration, 'first flush system' etc?
Many thanks,
Paul

I have had an "enclosable veranda" build in 2014. It is completely made out of platics, including the roof and rainpipes. This rain is collected inside, in a standard rainwater container, and used almost excusively for the tanks in this veranda. You will appreciate, I can't devide between first rain and later rain, I get it all

Apparently, my rain in Nijmegen, NL, is good. As you live in Manchester, being mostly east of Liverpool, the question is - how much air pollution does one find in Liverpool? Can't answer that for you

Many thanks for your thoughts. You're right, I'm a bit west of Manchester and the wind normally blows from the west, so the main sources of pollution are likely to be in the Liverpool area (including Warrington and Runcorn). There's a fair bit of heavy industry including oil/chemical plants in the area.
We have pretty strict air pollution laws here, but I don't really have a feel for how that might translate into fish-harming pollutants in the rain.
So perhaps harvesting rainwater for the fish isn't such a great idea.
Thanks again
Paul

Here is my set up. In the future I would like to install another storage barrel or two inline.
I can't speak to pollution issues in the UK, but if you are that concerned I would just place a big bag of activated carbon in the bottom of the rain barrel.
-Shane

Many thanks Shane. Perhaps I'm over-thinking it! Using some activated carbon is a good idea to solve pollution worries.

I started with half a dozen uncovered summer tanks in my garden, and later I realized that the rain, falling into the tanks could have done harm.

You could do something similar in spring: Take a container (better large, in order to stabilize temterature fluctuations), put it in full sun and fill it.

I used tank water in March, let it get green and later red from the Daphina, which I fed to my fishes. Than te water was claen, and kept claer. Mid May you can put subtropical fishes in.

After a few rains, you will know whether the rain is acceptable or not.

If no Daphina start, this can either be a sign of bad water - or of too few algea. They enter the water on the feet of bathing birds - but obviously, you can also introduce them yourself.

Thanks!
I do have a couple of outdoor troughs in a sunny place which have a good population of daphnia in the warmer months - they are used as fish food. I guess the rain can't be too bad then.
Cheers,
Paul

Hi all,
If I started again I would buy a thousand litre IBC, rather than separate water barrels.

I have always used rain-water, and I've used the Daphnia bioassay(viewtopic.php?t=37711&start=20 ) for the last 20 years without any problem.

cheers Darrel

Mol_PMB wrote: ↑03 Sep 2017, 15:11 Thanks!
I do have a couple of outdoor troughs in a sunny place which have a good population of daphnia in the warmer months - they are used as fish food. I guess the rain can't be too bad then.
Cheers,
Paul

I´d say - if the water is good for Daphina, it is good for fish

Thanks again. I think the IBC would work well for me. For domestic usage a black one is recommended to prevent algae growth, black ones are a little bit more expensive and I guess algae isn't such a bad thing for fish usage - i certainly have plenty in my tanks!

I got a green one, which does not get much light, but there are no algae in it. In fact, if I have some Lemna there, they die. After all, clean rainwater does not contain any nutrients.

Rain can contain a bit of nitrogen, due to air pollution but no more. And plants need more to grow