Pond Water Change

by Howard
(Jamaica West Indies)

Hi
I'm a subscriber to your gazette. I have gold fish in plastic tubs made from water tank material.

Water filters to a sump reservoir. Water is getting more expensive where i live in Jamaica.

Is there any way that rain water harvesting can be used for topping up the reservoir. Part of my system is covered with shade cloth

Is there some way to treat it?

I have received answers from you in the past.

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Grant's Reply

Hi Howard

What an impressive setup you have!

Yes, water is becoming an expensive commodity, and I suspect it will become more expensive due to global warming.

Where I live, we presently have water restrictions which is stopping me making scheduled water changes.

If you have a clean source of rainwater, I would definitely use it.

The only two problems are:

1. Making sure there are no chemicals such as horticultural sprays on any surface such as a roof from where you are collecting the water. The usual practice when collecting rainwater for drinking is to divert the flow for 30 minutes to allow for anything hazardous to be washed away.

2. If the rainwater is to be added to existing water in the sump, unless over 50% is replaced I wouldn’t worry about it.

If more than 50% will be replaced, or you are doing a full water change using only rainwater, I would add plain 100% un-iodized cooking salt at about a teaspoon per gallon.

Another thing to check is the pH of the rainwater compared to your usual water source to see how close it is.

Clean rainwater has a pH value of between 5.0 and 5.5, which is slightly acidic. Adding the salt would raise the pH slightly.