
How Many Fish Can I Put in My Tank? Honest Stocking Guide
The inch-per-gallon rule has killed more fish than any other piece of aquarium advice. Here's what to use instead.
8 min read
Height at the back, where a tank usually looks empty.
Height at the back is where most tanks look unfinished, because that is where the equipment lives. Tall planting hides heaters and cables and gives the tank depth.
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Colour: Green
Why you'll love it
Most beginner tanks are furnished at the front and empty behind. One tall plant at the rear hides the heater and the cables, and does more for the look than three small ornaments.
Shy species hold in the open far longer when there is something to bolt into. Planting the back gives them that without eating into the swimming space at the front.
Live stems in a low-light tank melt and foul the water. These need nothing, which is the honest answer for anyone who wants a planted look without a planted tank's workload.
Good fit if
Look elsewhere if
Visually, tall background planting does most of the work in a tank. It hides equipment, gives the scape depth and provides cover that fish will genuinely use. None of that requires the plants to be alive, and a tank with good artificial planting looks considerably better than one with struggling live stems.
What you lose is the biology. Live plants consume nitrate and compete with algae for nutrients, which is a real contribution to water quality. Artificial plants do neither, so the water change schedule that keeps nitrate down matters more rather than less.
The failure mode with cheap artificial plants is painted or dyed colour leaching into the water. It discolours the tank, and depending on what has been used it is not something you want in there with fish. It also fades, so the plant that looked good in month one is grey by month six.
Colour moulded through the plastic cannot bleed, because there is no surface layer to come off. It also cannot fade unevenly, so the plant looks the same after a year of light as it did on the first day. That is worth more than it sounds in a tank lit for seven hours a day.
Tall at the back, mid-height in the corners, short at the front is the standard arrangement and it works because it mirrors how planting grows in natural water. Leave a clear swimming lane through the middle rather than filling the tank wall to wall, since a densely packed tank looks impressive from the front and leaves active fish nowhere to go.
Push the weighted base into the substrate so it is covered, which both hides the base and stops the plant being knocked over. A group of three of the same plant reads more naturally than three different ones, and mixing one or two live stems in among artificial planting is a reasonable middle ground.
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The details
| Colour | Height | Notes |
|---|---|---|
| Green | 45 cm | The most natural-looking option for a background |
| Red | 46 cm | Works as a contrast accent among green planting |
| Orange | 49 cm | Tallest, for deeper tanks |
Measure the water depth rather than the tank height, since the plant should sit below the surface. In a tank under about 40 cm deep these will stand proud of the water.
Good questions
No. The colour is in the plastic rather than painted on the surface, so there is nothing to leach. Rinse it under a tap before it goes in, as you would any new ornament.
At 45–49 cm it suits tanks around 45 cm deep and up. In a shallower tank it will bend over at the surface, which some people like and some do not.
Bed it into the substrate rather than resting it on top. In bare-bottom tanks it will need weighting or tucking under a piece of hardscape.
No. The colour is moulded through the plastic rather than painted on, so there is no surface layer to bleed or fade.
Measure water depth, not tank height. At 45 to 49 cm these suit standard-depth tanks and deeper. In a shallow tank they will stand above the surface.
The base is weighted, and pushing it into the substrate covers it and anchors it properly. In very fine sand, bury it a little deeper than you would in gravel.
Last reviewed August 30, 2026
Advice

The inch-per-gallon rule has killed more fish than any other piece of aquarium advice. Here's what to use instead.
8 min read