Hydroponic Tower Maintenance: Cleaning & Care
Growing food is naturally a little messy. Roots grow. Leaves fall. Nutrient water circulates. Plants come and go. And after a while, the beautifully clean tower you started with begins to look like it has actually been growing something.
Because it has.
A little residue or build-up inside a hydroponic tower is normal. What matters is knowing what you're looking at, when it's time for a clean, and how much cleaning is actually necessary.
The good news? It's really not complicated.
Think of it a little like doing the dishes. You don't need everything to look permanently brand new. You just need to give your growing system a good reset from time to time so water can keep moving freely and your next plants have a clean place to grow.
How often should you clean a hydroponic tower?
There isn't one magic number.
A good time to give your tower a proper clean is between crops or when you're doing a significant plant change. If you're continuously growing and replacing plants, use the condition of the tower as your guide.
With my own FlowGrow, I find a more thorough clean often falls somewhere around the 6–8 week mark, but sometimes it needs attention earlier and sometimes it can comfortably go longer.
Rather than watching the calendar, have a look at what's happening.
It might be time for a clean if you notice:
- visible build-up around the planting sites
- slippery or discoloured surfaces
- algae developing where light reaches nutrient water
- plant or root debris accumulating in the reservoir
- sediment or mineral deposits
- build-up around the pump
- water flow that isn't behaving as it normally does
Small jobs along the way make the bigger clean considerably easier too. Removing dead leaves, stray roots and plant debris as you notice them takes seconds.
What actually builds up inside a hydroponic tower?
This is one of those things that can look alarming until you know what it is.
A hydroponic system brings together water, nutrients, plant roots, light and organic material. Over time, that can leave several different kinds of build-up.
Algae
Algae needs light, moisture and nutrients to grow, which explains why hydroponic systems can provide rather appealing conditions for it.
You may see green growth where light is reaching nutrient-rich water, particularly around openings or other exposed areas. Keeping light out of the reservoir and nutrient solution as much as possible helps reduce it.
Biofilm
Sometimes wet surfaces develop a slippery film rather than obvious green algae.
Biofilm is a community of microorganisms attached to a surface within a protective layer. Hydroponic systems aren't unique in developing it. Any environment where water and organic material continually meet can develop biofilm.
It's one reason physically cleaning the surfaces of the system matters.
Nutrient and mineral deposits
Not every mark is algae.
Dissolved nutrients and minerals in your water can leave deposits behind. Hard water can contribute additional mineral build-up, and nutrient salts can accumulate or precipitate in parts of a hydroponic system.
Some staining may remain even after you've cleaned the surface. That's okay.
A hydroponic tower is a growing environment, not a kitchen appliance. It doesn't need to look brand new every few weeks. It needs to be clean enough to keep water moving freely and give your plants a healthy place to grow.
Roots and plant debris
Plants are living things, so expect a little organic debris too. Fine roots, old root material, fallen leaves and other plant matter can eventually make their way into the system or reservoir.
Removing this material regularly prevents it from accumulating around the pump and water pathway.
Do you need to pull your tower apart every time?
No.
This is probably one of the biggest misconceptions about cleaning a hydroponic tower.
Sometimes I clean my FlowGrow assembled. Other times I take the layers apart. It depends entirely on what I find.
If the tower has relatively light build-up, the water is flowing properly and I can reach the areas that need attention, I'll leave the tower together and clean the reservoir, planting sites and accessible surfaces.
If there's heavier internal build-up, a lot of old root material, persistent algae or biofilm, or I simply think the tower needs a proper reset, I'll dismantle the layers and clean them individually.
You don't earn extra hydroponic points for taking the entire thing apart every time.
Clean what needs cleaning.
Taking the tower apart: The tower sections can feel firm, particularly the first few times you separate them. Hold each section securely and gently wiggle from side to side while pulling apart. Avoid forcing it in one direction. The connections generally become easier to separate after the tower has been assembled, used and cleaned.
How I clean my FlowGrow tower
Before you begin, remove your plants and net pots as appropriate and switch the pump off at the power supply.
Drain the old nutrient solution from the reservoir.
Before you drain it: Your old nutrient solution doesn't necessarily need to go to waste. You can use it to water garden plants or houseplants. If you're growing leafy plants, Grow solution is a natural fit. If you've been using Bloom, use it around flowering or fruiting plants instead.
Then start with the obvious stuff.
1. Remove loose plant material
Pull away old roots, leaves and any loose organic debris you can see. This makes the actual cleaning much easier and prevents debris simply moving somewhere else in the system.
2. Clean the reservoir
Empty the reservoir completely and rinse away loose sediment and plant material.
Give the inside surfaces a proper clean, paying attention to corners and anywhere residue has accumulated.
The reservoir doesn't need to be immaculate enough to serve dinner from. You're removing the accumulated material from the previous growing cycle and creating a clean starting point for the next one.
3. Clean the planting sites
These are the fiddly little characters.
The planting pockets naturally collect marks and residue because they're right where plants, water and light meet.
A cloth or small brush will do the job.
I've started using a small rechargeable electric cleaning brush to get right inside the planting sites. It's completely optional, but after cleaning your ninth little planting pocket by hand, you'll probably understand the appeal.
Work around the inside of each planting site and remove any visible build-up.
4. Check the inside of the tower
If you're cleaning the tower assembled, rinse and clean as much of the internal surface as you can reasonably reach.
If you've dismantled it, you have much better access to the inside of each section. Remove old roots, organic material and visible build-up and give each section a thorough rinse.
This is also a good opportunity to inspect the pieces while they're apart.
Cleaning the pump and water pathway
Your pump does a lot of quiet work.
In a FlowGrow system, it pushes nutrient water from the reservoir up through the central hose to the Flow Cap. From there, water is distributed across the top of the tower and cascades back down past the roots before returning to the reservoir.
That means keeping the pump and water pathway clear is more important than obsessing over a cosmetic mark on the side of the tower.
Remove any root material or debris around the pump and its intake. Clean accessible pump surfaces and check that nothing is restricting water movement.
Once everything is back together, watch the Flow Cap when you restart the system and make sure water is distributing normally.
Pump running but no water at the Flow Cap? Occasionally, an air pocket can form in the pump or hose after the tower has been emptied and refilled. If you can hear the pump running but no water is reaching the Flow Cap, switch the pump off and gently tilt or move the pump while it is fully submerged to help release trapped air. Switch it back on and check the Flow Cap again. You may need to repeat this once or twice until normal water flow returns.
What I use in my own FlowGrow
You don't need a cupboard full of specialist hydroponic cleaning products to maintain a tower.
For the physical clean, water and a suitable cleaning brush will do much of the work.
One additional product I personally use is Forsana Hydroponics Plus.
Hydroponics Plus is a New Zealand-made, silver-enhanced 7.5% hydrogen peroxide product formulated specifically for hydroponic use. Forsana lists several uses for it, including helping control algae and biofilm, sanitising reservoirs and hydroponic equipment, preparing water and breaking down organic build-up.
It's not something you need in order to own or successfully use a FlowGrow. It's simply something I've found useful in my own maintenance routine.
Forsana also provides directions for using Hydroponics Plus within an operating hydroponic system. Because concentrations and product instructions can change, follow Forsana's current label and usage instructions rather than relying on a dilution rate copied from an older article or bottle.
Important: don't assume all hydrogen peroxide products are interchangeable. If you're using any treatment in a system growing food, use a product intended for the application and follow the manufacturer's current directions.
Cleaning and sanitising aren't quite the same thing
This distinction is worth knowing.
Cleaning physically removes roots, sediment, residue, biofilm and other material from surfaces.
Sanitising uses an appropriate treatment to reduce microorganisms after those surfaces have been cleaned.
The order matters. Physical build-up can get in the way of a sanitising treatment reaching the surface properly, which is why the scrub isn't the bit to skip.
The simple version: get the muck off first. Then, if you're using a sanitising product, use it according to its directions.
How to keep your tower cleaner between resets
You don't need to spend every Sunday cleaning your hydroponic tower.
- remove dead leaves and loose plant material when you see them
- keep the reservoir covered so nutrient water isn't unnecessarily exposed to light
- check around the pump for roots and debris
- keep an eye on normal water flow
- wipe or rinse accessible build-up before it becomes substantial
- refresh your nutrient solution as recommended
- give the system a proper clean between major crop changes
The more you notice along the way, the less dramatic cleaning day becomes.
What if my tower doesn't come completely white again?
Don't panic.
White plastic is particularly good at showing every mark a plant has ever thought about making.
Some mineral staining or discolouration can remain even when the actual residue has been removed.
What we're interested in is the condition of the system, not whether it photographs like a brand-new tower.
If surfaces are clean, loose organic matter has been removed, the reservoir and pump are clean and water is flowing properly, a stubborn mark isn't necessarily something that needs further scrubbing.
There is such a thing as clean enough.
A simple FlowGrow maintenance rhythm
If you'd rather not remember everything above, this is the bit to keep.
Remove dead leaves, stray roots and debris. Check the reservoir and make sure water is flowing normally.
Drain the nutrient solution. Clean the reservoir, planting sites, pump and accessible parts of the tower. For my own FlowGrow, a more thorough clean often works out at roughly every 6–8 weeks, depending on what I'm growing and what the system looks like.
Take the tower sections apart and give everything a deeper clean.
That's really it.
A little maintenance goes a long way
Hydroponics can sound technical until you actually live with a system for a while.
Then a lot of it becomes surprisingly ordinary.
You top up some water. You check your plants. You pick something for dinner. Every so often, you empty everything out and give the tower a good clean.
Not particularly glamorous.
But neither is doing the dishes, and we've somehow survived that.
The reward comes afterwards.
Fresh nutrient water goes back in. The tower is ready again. New roots begin growing down through the inside, and before long the planting sites you just scrubbed are disappearing behind basil, lettuce, herbs or strawberries.
Then you get to make it dirty all over again.
And really, that's rather the point.
Helpful next steps
Once the tower is clean and ready to grow again, these guides will help with the next part.
FlowGrow Feeding Guide
Refill with fresh water and the right amount of nutrients for your plants.
Understanding pH and EC
A straightforward guide to nutrient strength and pH for home growing.
Do hydroponic towers get bugs?
The honest guide to pests, prevention and what to do if something appears.
Grow it. Clean it. Grow again.
A little care keeps the water moving and your tower ready for whatever you want to plant next.
