Backyard Aquaponics
A place to discuss aquaponics

I'm interested in starting an aquaponics system, but I live in a town with hard water and I'm assuming that it also contains fluoride and chlorine. I have read that hard water will kill the fish but am not sure if this is true. I would like to know what my alternatives are to this problem. I want to use the most natural and healthy way possible. I thought of distilled water but then you have to have a source of oxygen to supply the water with as well as minerals/nutrients because of the water being distilled. Would a hydroponic setup be more fitting to this problem?

Is it drinking water?

Then it should be ok.

Make sure to run the system with no fish (with air blower on) for a while to ensure chlorine gases off.

let me clarify here.

I have a bore, the water is just *barely* drinkable - very hard and tastes awful.

My fish are fine.

You need to find out what the water is treated with. If chlorine, then you can simply let it outgas and it will be safe for fish. If Chloramine, then you may need to neutralize it or filter it to make it safe for the bacteria, trick here is some of the water conditioners for aquarium use are not good for food systems so research that. I can't give too much advise about using city water as I have a well that provides great drinking water.

However, my well water is hard water, that isn't really such a bad thing though depending on how hard it is. Aquaponics has a tendency of going acidic and hard water can help counteract that. In my case, my well water has a pH of around 8 (after outgassing) but in an unbuffered AP system the pH will still drop as the system is cycled up. There are some cases where the source water might be so hard that even long term the pH of the system remains above 8 and has been an issue for the plants.

I was looking at a previous thread regarding hard water and someone said their vege plantings didn't do well.

I have bore water and the fish (goldfish and sp) seem to love it but many of the pond plants seem to die off except for many of the Australian native grasses.

Anyone else care to comment on their experience with veges in hard water?

Hard water (limestone in my case) kept my plants from going beyond the sprout stage. Alternatives are bottled spring water and rain water. I'm starting to learn to measure each bottle of spring water for my 10 gallon system. The spring waters can come from different springs for the same label sometimes which can make them different (aka Ozarka). Another alternative is to buffer the system down. Liquid additives are not sustainable to "buffer" a system and therefore only useful as a last resort to save a system in times of emergency. Continuous very slow drip of liquid may work but we're mostly too lazy around here to monitor that. Maybe TCLynx could verify the use of bogwood(driftwood) from a local river?

You put bottled spring water in your AP? That sounds horrendously expensive.... and wasteful of plastic.... ?!

It wasn't raining much the past half year here.

I have not used wood to acidify water but some people do use drift wood for aquariums.

You can get a report about the tap water from whoever the water utility is. It should tell about the chemicals used to treat the water and such.

Most fish like somewhat hard water but that can vary depending on the fish type. I use well water out of a limestone aquifer. My pH is stable at 7.6 because of the 40% shells I have as media. If I had used 100% river gravel as media, I'm sure my pH would be much lower. My particular had water is not hard enough to keep my pH high for long against the action of the bacteria.

Aquaponics is a balancing act. Most fish are fairly happy in a wide range of pH though they don't like it to change quickly. Most plants would prefer the pH be lower but the bacteria can crash if the pH drops too low (below 6.) Most buffers will buffer pH up to 7.6 or 8 which is higher than most plants like and tends to lock out Iron and some other nutrients. If your media is buffering your system up, there is really no point trying to bring the pH down with acid, it won't do any good till you dissolve all the media and is likely to cause harm by bouncing the pH. You can keep pH up using a buffer like shells.

If it is just your tap water that is High pH, you could probably treat it with an appropriate acid to bring it in line with an appropriate pH before adding it to a system but It might be worth running some tests in buckets to see if the acid treatment lasts long term or if the water is so hard that the pH just bounces back up. My tap water after outgassing has a pH of 8, my systems with their buffers have a pH of 7.6 unless the bacteria are working overtime in summer. I have used acid to adjust the pH of my tap water to about 7.6 before doing water changes on my indoor aquarium system so that I'm not bouncing the pH up with the addition of the high pH tap water. I have to do water changes on that system as there are not enough plants in it to use up the nitrates.

So adding a large amount of shell grit to your sump tank would help buffer up the pH and adding more gravel will buffer it down yes?

For a city water filter, i use a 4"dia x 10' PVC pipe filled with activated charcoal, so that no declor is needed for top ups...... And I always run the water through the filter very slow, so that it has plenty of dwell time in the filter, so that it removes almost all of the clor, and the filter will last a very long time that way.....

I also use a activated charcoal filter on any rain water i use.......

The gravel is neutral, does not have an effect.

Well shell grit will buffer the pH up to a point (tops out usually at 7.6 but if you don't use so much it can be used to keep the pH at a lower level, like some aim for 6.8.)

Gravel, well that depends on the type of gravel. The gravels we usually recommend for AP generally don't have any particular effect on the pH directly. Some gravels like Limestone would have an extreme buffering effect and may cause the pH to stay well over 8 indefinitely. There is no good way to buffer pH down within a system that has too much of a strong buffer in it.

Hard water will usually not cause too much trouble once a system is established. My well water is hard and if I make sure to set up a system with pH neutral gravel, once the system cycles, the pH will drop and I will need to add shell grit to keep the pH in a good range. Since my well water is hard, I won't need quite as much shell grit as some one with soft or acidic water because topping up the system with my hard water will act a bit like adding some buffer to the system when I do top up.