Tried watering my monstera with leftover aquarium water for 3 weeks

The leaves went from dark green to almost yellow and started curling at the edges. I learned the hard way that fish waste has way too much nitrogen for houseplants. Has anyone else burned their plants trying to be eco-friendly?

2 comments

2 Comments

grant.felix17d ago

Actually its not just the nitrogen, its more about the buildup of salts and minerals too. I learned this the hard way with some peace lilies a while back. Aquarium water has all sorts of dissolved solids from fish food and waste, plus whatever treatments you use like dechlorinator or plant fertilizers. Those salts build up in the soil over time and basically cook the roots. Your monstera is showing signs of salt stress with those yellowing edges. You need to flush the pot with regular water to wash out the excess, probably do it a few times over the next week. And if you want to use aquarium water again, dilute it like 1 part aquarium water to 10 parts regular water, and only do it once a month max.

hart.sage17d ago

Man, you just described my exact mistake last summer. I thought I was being all eco-friendly dumping old tank water on my herbs and basil, but I basically gave them a slow salt poisoning. Its like I was trying to water them with ocean water by the end. I lost a whole rosemary plant before I realized what was happening, the leaves just curled up and went crispy brown. I still feel dumb about it when I look at that sad little pot.