Plants in Extreme Hard Water

[LemonFish7]

The city where I live has extreme hard water (460 ppm or 359-564 mg/litre, from the sources I found) and I am trying out live plants in my aquariums. I started with anubias, as I heard they were a good choice for beginners and for hard water but after a month or two it was very obvious that they were dying despite decent lighting and fertilizer. I desperately scoured the internet trying to figure out what I could have missed, as I've been a long time viewer of the aquarium co-op channel, as well as a few other aquarium channels, and feel like I've picked up most of what I should need to know to grow basic aquarium plants. All I found was a single video that mentioned something to the effect of "at high pH/hardness nitrates/nitrites aren't soluble in water and therefore aren't available to plants" but I haven't been able to find any other sources mentioning this. The video also mentioned that the substrate, if undisturbed, can develop a different pH/hardness that can allow roots to live, so I moved my anubias to the substrate so that the rhizome is just showing but the roots are buried with some root tabs. after more than a month, one plant has bounced back a bit while the other is still looking quite sickly.

I was wondering if anyone has experience with growing plants in extreme hard water? I'd be open to any tips or advice. Also, if anyone knows more about the chemistry of nitrate/nitrites and can confirm or explain how this works, please hit me with the science. I'm trying to decide if it is worth it to experiment with more root-feeding plants or if I should give up for now and wait until my hobby has grown to the point where a water-softener or RO unit is worthwhile.

Thanks in advance!

[Cory]

My current fish room has higher hardness, and so doe sour Kentucky warehouse. Both have growing plants. Do you have a green thumb? Whats your setup, have pictures? Which plants are you trying to grow? Most often we find people are "doing all the right things" and but not understanding what they are doing. Often left searching to an answer, and start trying random things, like plantings an anubias into substrate for different ph/hardness when the Anubias prefers harder water.

 

At a very basic and predictable level. Plants want light, fertilizer and time. Now you just need to figure out which one of those you aren't delivering.

You have an anubias, they can basically grow in the dark. You could be giving it too much light. Whats the nitrate level from easy green in your aquarium?  Often people can put in 1 dose a week not realizing their tank needs more and msot of the week the plants are starving. Do you have algae? they eat up fertilizer much faster than plants. How long is the light on? Plants basically can't photosynthesize more than 12-14 hours and algaes can strip fertilizer out after that.

I'd start with nitrates, pictures of the overall tank, how often you dose, what light you're using at what intensity. From there we can trouble shoot some more.

[Chris]

I'm gonna second that hard water doesn't typically inhibit plant growth IME. I have very hard water here in central KY (off the charts on most test kits) and I've never really had any issues with plants, or any fish for that matter. There are others on here that know far more about plants that will be of more help, but I think you may be on the wrong track by looking at water hardness in this scenario.

[LemonFish7]

@Cory and @Chris, thanks for the responses.

I have a decent green thumb when it comes to terrestrial plants, but aquatic plants are new to me. I have two tanks, a 20 Gal. tall with a small school of cherry barbs and a chinese algae eater (the clown-puke gravel in the pictures), and a 10 Gallon with only a smiling acara and a few trumpet snails (blue gravel). I have an anubias minima in the 20 tall, originally it was affixed to a piece of decor and not in contact with the substrate at all. I also have an anubias barteri 'wrinkled leaf' in the 10 gallon, which was affixed to a rock where the roots had some contact with the substrate. The A. minima in the 20 is in worse shape, if hardness has made the nutrients unavailable I suspect this is because it had no contact with the substrate and so had no nutrients. The A barteri was also looking bad but has bounced back better, looking almost healthy now, I think due to having roots already in the substrate. I had previously been fertilizing with aquavitro synthesis as I had bought this before easy green was available in Canada (where I live). I was dosing above the recommended rate because I never saw any nitrites or nitrates with the test strips (aquarium co-op brand of course). In both tanks I had black beard algae. When I moved the anubiases to the substrate, I also stopped fertilizing the water , supplementing only with root tabs, figuring that it would be a waste to continue if it wasn't available to the plants as I suspected. Now, the black beard algae has practically disappeared and the 20 is nearly spotless aside from a bit of green spot algae and black algae on the plants that the barbs keep at bay. Since I stopped fertilizing the water the 10 gallon has shifted from out of control black beard algae on the fake plants to mostly brown and green algae on the glass which I recently got the trumpet snails to deal with.

As far as lighting, the 20 gallon has a 20" easy LED set to 3 clicks, and the 10 had a 10" JC&P light set low, and has since been upgraded to an 18.5" JC&P light set as low as possible. Both tanks are lit  3 1/2 hours in the morning, and 6 in the afternoon/evening. If I recall correctly I also adjusted the light schedule a month or so ago, but they were receiving less light before, 4 hours and 4 hours I believe.

TLDR: the anubias in the 20 gal, relatively algae-free tank is doing the worst and the anubias in the more algae-prone tank is doing better. Nitrates and nitrites are null. I am not currently dosing fertilizer but when I was dosing heavily with aquavitro synthesis, nitrates and nitrites weren't showing either, and I also had black beard algae that has since disappeared. Lights are at low intensity and for 9.5 hours total per day.

Edited May 14 by LemonFish7
added @

[Cory]

If Those were my tanks. I'd try getting some vallisneria, , some java fern, and a stem plant and give them a try. It is hard to balance with only 1 plant. It looks like over time the anubias can thrive once they find some balance. It will be decently hard without more plants and having lights on. Also I'd have the light on like 8 hours until you get some more plants to try.

[JettsPapa]

My water is also very hard.  Corkscrew val, Mexican oak leaf, guppy grass, pearl weed, hornwort, and a number of crypt species do well for me.

Susswassertang is growing well, but it had a very long acclimation period.

Anacharis is doing very well in one tank, but struggles in the rest of them.

[jwcarlson]

I think you'll find that nitrogen availability is a bigger deal than water hardness.  I have very hard water and I keep my nitrates pretty low.  I've had good luck with salvina, dwarf water lettuce, hornwort, anubias, dwarf water lily, anacharis, guppy grass... 

But if your nitrates are at or near zero all the time, you're going to struggle.

Edited May 14 by jwcarlson