How to Water Houseplants In LECA

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One of the main advantages of using leca over soil is that you can look at the reservoir, see if it’s empty (or not) and water accordingly.

Once the water in the reservoir is gone, add more. If there’s still some in leave it.


With plants in soil, if you water them before they’re ready, you risk them getting root rot and dying. We don’t have that issue with leca, so long as the roots aren’t submerged (and many plants are happy to have their roots at least a little submerged).

For those of us that are super, super busy (or in my case, have ADHD and have to schedule EVERYTHING otherwise it…won’t get done) this is great because you can assign a day to water your plants.

Let’s say you choose Saturday to be your plant day. Every Saturday you can go around and top up the reservoirs, whether they’re bone dry or still half full.

Theeeeeen once a month you can flush all your pots, make up your nutrients and you’re good to just add water until next week.

(Please don’t tell anyone, but it’s usually AT LEAST two months between flushings at my house, and that’s pretty good going.

How to water a plant in LECA

You water leca exactly the same as you would water soil – pour it over the top and try to coat the surface evenly.

If you’re using the shower method, then you let the water run out of the bottom of the pot (like soil) and you’re done.

This is good for plants that have only been recently transitioned to leca and you suspect might be tricky.

If you’re transitioning plants that really like to dry out a lot between waterings, or are sensitive to overwatering, like Succulents and hoya, the shower method can help ease the change.

If you’re using the reservoir method you just fill up the reservoir.

If you’re diligent and well organised (not me), you can mark the inside of the cachepot with a sharpie at the third full mark, so you don’t have to guess (because if you take out the plant and fill up a third of the pot, the inner pot will displace the water and it’ll end up like half full).

I just guess, but I wish I was the kind of person that marked the pot. One day!

Do you water leca less often than soil?

It really depends on the plant and you.

Some plants will take a looooong time to go through the water in the reservoir, and some people prefer to let the reservoir dry out before filling it up. So theoretically, you could go months between waterings (depending on the plant).

I have a Marble queen Pothos that only needs her reservoir topping up every three months, and she’s thriving.

marble queen pothos in leca

I know she’s getting a bit of green in the newer leaves, but I honestly think it looks prettier than the whiter ones. She has a much whiter vine on the other side, but the leaves brown pretty quickly- you can just glimpse it in the top left of the photo.

Whether you leave the reservoir to get dry or top it up weekly/daily/whenever is totally personal preference – I ideally like to keep mine topped up, but inevitably some slip through the cracks.

My Syngoniums are thirsty monsters, and I think they go through more water in leca – they also grow way faster too, in my experience. Makes sense I suppose.

Sometimes I chance upon a plant and it’s bone dry. These things happen! I also noticed that if the roots have grown down into the leca the reservoir dries up more quickly…

…Probably because it’s in a pot that’s far too small but I’m too lazy repot it.

Since leca is so good at holding water, it’s rare that plants get too dry – I rarely see my Syngonium droop anymore, which is good.

Syngoniums can take an age to perk up again – my Trileaf wonder is a real dive in that respect.

Can you overwater leca?

Yes, I suppose technically, but it’s not as easy to do as it is with leca.

Despite what many leca enthusiasts will tell you, you can still get root rot with leca.

Here are some of the ways you can overwater leca:

  • You have the roots too low in the pot, or the reservoir too high

As I mentioned before, many plants are totally fine to have their feet dangling in the water, but some, usually newly transitioned plants, don’t like it at all.

If you see any brown mushy roots just trim them off, do a hydrogen peroxide bath if you’re worried, and start again with a lower reservoir.

  • You let the roots dangle in deoxygenated water

This shouldn’t be an issue unless you have a very finicky plant, or you have basically all of the roots in water, but it can.

Root rot is caused by bacteria that thrive in low-oxygen environments. Leca is a terrible place for this bacteria, because it’s, like, 30% gaps.

But if you have too much water, and let it go stagnant, then the plant won’t be able to get any oxygen to its roots.

  • You didn’t clean enough soil off the roots

Read my leca guide for tips on cleaning roots.

I’m not the best at this, since I’m quite, er, heavy-handed, and end up snapping roots after a while.

If you’re in the same boat, I’d recommend keeping the plant in just water for a couple of weeks, to help ease more soil away.

To be honest though (you’ve probably been waiting for me to say this) I’ve put some pretty dirty roots in leca and they’ve been FINE.

Not like, dirty dirty, but certainly not the pristine white roots you see on Instagram.

Should you add nutrients every time you water leca?

Again, this is a matter of personal preference.

I don’t. I only add nutrients every month (*cough* or two *cough*), and just top up with water in between.

If you want your plants to grow ENORMOUS and they have a tonne of light and are really healthy, then by all means add nutrients every time you water.

I would be quite diligent about monthly flushings though because you don’t want minerals to build up too much and poison your plants.

Whilst I would LOVE for my plants to grow huge, I don’t really have the space for that (or the desire to keep up-potting them) so I only fertilise when they’re being flushed.

(While we’re on this topic, leca is great for people who want to keep their plants small because it’s so much easier and less messy to trim the roots).

How often do you need to totally change the reservoir with leca?

I suppose technically you don’t ever NEED to totally change the reservoir, but practically, it’s best done when you’re flushing your plants.

Algae and general debris from the plants and the leca build up quite quickly in the cachepots, so I like to give them a quick scrub when it’s flush day.

How often should you flush leca?


Again, do as I say, not as I do.

I don’t think that there’s any benefit to flushing more than once a month.

Monthly is ideal. Optimal.

Two months is FINE.

Other plant caregivers may protest, but some of my plants my plants haven’t been flushed in omg FOUR months.

I am ashamed.

My plants are all doing well.

If you’re unsure about what flushing is, it’s just running plain water through the leca and rinsing off that white crust that can form on the surface.

Can you water leca with tap water?

So when you first start researching leca you’ll see a lot of people wanting on about pH test kits and stuff.

I bought one, made up my nutrients, and tested it. pH was spot on. I repeated this every time I added nutrients and my pH was always fine.

Due to the apparent stability of my tap water, I decided that it would be fine to water my plants with it.

Most people using leca – or the ones I watch (on YouTube – not through the window) – use filtered water.

Not me. I just get it right from the tap.

Again, my plants are fine BUT

I come from a particularly beautiful part of North Yorkshire that has freaking awesome tap water.

You may have to work out whether or not you can use you tap water using trial and error BUT if you water your soil plants with tap water and they’re ok, I’m sure your leca ones will be too.

Will aquarium water replace the nutrients in leca?

The answer to this is, I’m afraid, it depends.

If you’re somewhat into fish, you’ll know that they all poop different amounts. A massive shoal of neon tetras won’t poop half as much as one pleco.

Nothing on EARTH poops as much as a goldfish (I’m being facetious – this isn’t literally true, and I don’t want you to Google how much animals poo).

Also, the type of filter you have, and how often you change your water will depend.

Our aquarium is stocked with medium fish (a lot of corys, some rainbows, four smallish angelfish) and is 240 litres. We have a mahoosive external filter, as well as another smaller one.

The water is very well filtered, yet the plants I water exclusively with aquarium water (and don’t fertilise with anything else) do pretty well.

It’s really just a matter of testing out using just aquarium water and then supplementing with nutrients if your plants look a bit chlorotic and sad.

(I also grow house plants in my aquarium and they’re doing great BUT my boyfriend adds fertiliser to the aquatic plants and i don’t know if that will affect mine).

I hope this was helpful – if you have any questions feel free to leave a comment and I’ll get back to you asap.

Caroline Cocker

Caroline is the founder and writer (and plant keeper) of Planet Houseplant

2 thoughts on “How to Water Houseplants In LECA”

  1. Hi there! I enjoyed reading your post about lecca.
    I’m very new to the lecca world, & very excited at the same time. But, I’m concerned about the water here, cause it is partially filtered water, meaning the landlord says the water filter doesn’t work all that great. I have been using some bottled water when I have some, otherwise it’s the tap. I’m not seeing anything bad from it now, by I am concerned if I continue? Do you have any good advice for me?

  2. I use tap water, and I’ve never had any issues. If it’s going fine for now just keep using tap water, but if you start having issues then consider getting a jug water filter – it’s a bit more economical than using bottled water.

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