Everything we get asked, answered plainly. If your question is not here, email info@onefishtank.com and we will answer it and add it to this page.
The Modular Planted Floor
What is the Modular Planted Floor?
It is a planted aquarium floor built from separate lift-out modules instead of one loose bed of substrate. Each module holds its own substrate under a soft sponge layer, and plants root through the sponge. Because every planting zone is its own contained piece, you can lift one out, work on it, and put it back without disturbing the rest of the tank.
What problem does it actually solve?
The reason most people leave this hobby is not that planted tanks are hard to build. It is that they are miserable to change. Algae arrives, a plant melts, or you simply want a new layout, and the only fix is uprooting everything. The Modular Planted Floor turns that weekend teardown into three steps: lift the module out, rinse it, put it back.
How does the sponge hold plants down?
The sponge is elastic. You open a slit with tweezers, push the stem in, and the sponge closes around it the way fingers would, without crushing the stem. It grips immediately, so plants do not pop back up hours later, and roots grow down through it into the substrate below.
Do the modules move or float once they are in?
No. Filled with substrate they are heavy enough to stay seated, and once roots establish through the sponge the whole module holds together as one piece. You can pour water directly onto them, run the filter at full flow, and nothing lifts.
Can I see the seams between modules?
At first, yes, slightly. Within a few weeks plants and carpets grow over the joins and the floor reads as one surface. The photographs on our homepage are all real tanks with modules in them.
Is it patented?
The system is the subject of a filed patent application. We describe the design as patent pending rather than patented, because that is what is accurate today.
Algae, cleaning and maintenance
Does this stop algae?
No, and be careful of anything that claims it does. Algae appears in every planted tank, including ours. What changes is the cost of dealing with it. Instead of a teardown you lift out the affected module, rinse it in the sink, and reseat it. The algae leaves with the module rather than being scrubbed across your whole aquascape.
Why does waste behave differently in this system?
In a conventional tank, debris works its way down into the substrate where you cannot reach it without digging. Here it settles on top of the sponge and on the bare glass between modules. Lifting or even shaking a module releases that waste into the water column, where your filter can actually remove it.
Can I vacuum without uprooting my plants?
Yes, and this is the part people find hardest to believe. You lift a module with one hand and vacuum the bare floor underneath with the other, the same way you would move a chair to vacuum under it. Established plants will not pull out even under a strong siphon.
How long does maintenance take?
Less, and more importantly it stops being something you dread. A water change becomes an opportunity to tidy a module rather than a risk of disturbing the scape. We are not going to pretend it becomes zero, but it stops compounding as the tank matures.
What if I miss two weeks?
Nothing catastrophic. Tanks here have gone a fortnight untouched. If algae does take hold while you are away, recovery is faster than in a conventional tank because you can pull the affected modules, clean them properly outside the water, and put them back.
Do I have to lift out the whole floor?
Almost never. Problems usually start in one area, so one module is normally all it takes. But if a tank really gets away from you, you can lift every module out, clean them all, and set them back down. That is a complete reset without uprooting a single plant.
Switching a tank you already have
I already have a running tank. Can I convert it?
Yes, and it is one afternoon. Take the plants out, remove the old substrate, clean the glass, then seat the modules and replant. It is the last full teardown that tank will ever need, because from then on every change is done a module at a time.
Do I have to buy all new substrate and plants?
No. Your existing substrate goes straight into the modules, your hardscape sits back on top, and your plants get replanted into the sponge. Most people reuse nearly everything, so the switch costs an afternoon rather than the price of a new setup.
Will converting crash my cycle?
Your biological filtration mostly lives in your filter media, not your substrate, so keep the filter running and do not clean it in the same week. Test for the first fortnight as you would after any significant change.
Can I convert gradually instead of all at once?
Yes. You can start with a single module in one corner and add more when you are ready. There is no minimum number, and modules bought later work with modules bought earlier.
Sizes, files and printing
What sizes are there?
Nine footprints, every one a multiple of 35 mm so they tile together cleanly: Small 70x70, Slim 70x105, Medium 70x140, Square 105x105, Standard 105x140, Large 140x140, Wide 140x175, XWide 140x210 and Jumbo 210x210 mm. Each comes in three heights.
Which height should I choose?
H30 at 30.48 mm suits carpets and foreground plants such as hairgrass and Monte Carlo. H38 at 38.10 mm covers midground stems and most everyday planting. H50 at 50.80 mm is for background stems and heavy root feeders like swords and crypts. You can mix all three heights in one tank, which is something a single flat substrate bed cannot do.
How many modules does my tank need?
Use the calculator on our homepage. Enter the inside dimensions of your tank and it returns the exact list, with a layout plan. Measure the inside of the glass rather than the outside.
Do I need a 3D printer?
For the digital products, yes, or access to a printing service. The files are print-ready STL. Printed, ready-to-plant kits are in small-batch production and are not on sale yet. The free starter kit is the no-risk way to see whether the system suits your tank.
What is in the free starter kit?
Nine module files covering three footprints across all three heights, plus a PDF layout template you can print at true scale to plan your floor. No email wall, no trial period.
Plants, substrate and livestock
Which substrate can I use?
Your own. The module contains whatever aquasoil, sand or gravel you already prefer. You are not locked into a proprietary medium, and you can run different substrates in different modules in the same tank so each plant gets what suits it.
Can I keep sand and aquasoil from mixing?
Yes, and this is one of the clearest wins. The module wall is a physical barrier, so a sand zone and a soil zone stay separate permanently rather than blending into each other over months.
Will lifting a module disturb my fish?
Far less than a normal rescape. You are removing one contained piece rather than digging through a substrate bed, so very little clouds the water and parameters stay stable. Fish simply move out of the way. Good aquarium shops keep bare-bottom tanks for exactly this reason.
Is it safe for shrimp and fry?
Once the sponge is seated, shrimp and fish cannot get inside the module. Only plant stems pass through. Move slowly when lifting, as you would with any maintenance in a shrimp tank.
What about rhizome plants like anubias and buce?
Those should never be buried, in any system. You can rest them on the sponge surface or tie them to hardscape as usual. That is plant technique rather than anything the floor changes.
What this system does not fix
We would rather tell you this than have you find out after buying.
Algae on the glass
That is a light and nutrient balance problem, not a floor problem. The modules make the cleanup easier, because you can lift them out and reach every pane, but they will not change how fast it returns. That comes down to your photoperiod and dosing.
Cycling, fish disease and water chemistry
Unchanged. You still need to cycle a new tank, quarantine new livestock, and understand your water. The floor makes water changes easy enough that people actually do them, which helps, but it is not a substitute for the basics.
Light, CO2 and fertiliser balance
Still yours to manage. The modules solve anchoring and access. Whether a carpet actually spreads depends on light and CO2, and no floor design changes that.
One handling note, from experience
On a very mature tank, plants sometimes grow across and bind two modules together. Lift one at a time and check before pulling. It is a small thing, but you should hear it from us rather than discover it yourself.
Orders, shipping and returns
What does One Fish Tank sell?
Our main product is the Modular Planted Floor, available now as downloadable STL files. We also design custom themed aquariums built to spark curiosity in younger fishkeepers, and offer aquatic plants, 3D-printed accessories and gift cards.
How do I get my files after buying?
Digital products are delivered immediately after checkout. If a download link does not arrive, email us and we will send the files directly.
What is your refund policy?
We accept returns on physical items within 30 days of purchase, with no restocking fee and free return shipping. Items must be returned in their original condition. Email info@onefishtank.com and we will take care of it.
What is your shipping policy?
Physical orders are processed and shipped within 2 to 5 business days, with tracking on every shipment. Costs and delivery times vary by location and product. International customers are responsible for any customs fees, and we will always keep you updated if there is a delay.
How do I contact you?
Email info@onefishtank.com. A real person answers, and if your question is a good one it usually ends up on this page.