Let us start with the part the shop will not tell you, because it costs them a sale.
No animal fixes an algae problem. Algae is light and nutrients out of balance with the plants and maintenance in your tank. Buy a cleanup crew to solve that and what you get is an algae tank with more waste in it. Fix the cause first — our guide to identifying your algae covers that, and the answer usually involves your light hours.
Once the cause is handled, a cleanup crew is excellent. Here is who earns their place.
Nerite snails — the best glass cleaner there is
If you buy one thing off this list, buy nerites. They are the only common cleanup animal that reliably eats green spot algae, the hard green discs that weld to your glass and laugh at a magnet scraper. They also graze film algae off hardscape and leaves without damaging anything.
They suit where we live perfectly. Snail shells are built from calcium carbonate, and keepers in soft-water countries have to supplement to stop shells pitting. Dubai tap water is hard and alkaline, so ours grow thick glossy shells with no intervention. One of the rare cases where our water is a straight advantage.
The annoyance: females lay small white eggs on hardscape. They cannot hatch in fresh water — nerite larvae need brackish conditions — so you will never be overrun. Cosmetic irritation, not an infestation risk. Stock roughly one per 20–30 litres; more and they slowly starve.
Amano shrimp — the hair algae specialist
Amanos are the workhorse for hair and thread algae. At 4–5 cm they are noticeably bigger than cherry shrimp and correspondingly more effective — six will strip a mild outbreak in days. They are also relentless food thieves with no dignity whatsoever, which is worth the entry price on its own.
Caveats: anything with a big enough mouth will eat them, so no cichlids or large community fish. And once the algae is gone they need feeding like any other animal.
Otocinclus — brilliant, and fragile
Otos handle soft green film and brown diatoms on glass and broad leaves. Small, peaceful, entirely plant-safe. In a planted tank they are close to perfect — and they are also the most commonly killed animal on this list.
They need a mature tank. Otos eat biofilm as much as algae, and a three-week-old tank has none. Adding them to a freshly cycled tank is a slow starvation sentence dressed up as a purchase. Wait two to three months.
They arrive stressed. Most are wild-caught. Buy round-bellied ones rather than sunken, take your time over acclimation, and quarantine them like any new fish. Buy at least four, and keep blanched courgette on hand for when the algae runs out.
Bristlenose pleco — the pleco you actually want
Bristlenoses top out at 12–15 cm, so one is a reasonable resident in a 100 litre tank rather than a crisis. They rasp brown and green algae off flat surfaces and they are hardy. They do need driftwood as part of their diet, and they produce serious waste for their size — count them in your stocking maths as a fish, not as equipment.
The common pleco — the most regretted purchase in this hobby
Sold at 5 cm alongside everything else on this list. Reaches 40 to 45 cm — not eventually, not exceptionally, that is a normal adult and they get there fast.
What follows is predictable. It outgrows the tank in a year or two, largely stops eating algae once it discovers pellets, and produces waste on a scale that overwhelms the filtration on any tank that fits in a Dubai flat. Then the owner is trying to rehome a 40 cm fish nobody wants, in a market with very limited options.
If a shop offers you a "plecostomus" or "janitor fish" with no more specific name, assume common pleco and buy a bristlenose instead — same job, one tenth the eventual size. Our guide to choosing tank size around your fish is really about avoiding exactly this.
Also avoid Chinese algae eaters. Enthusiastic as juveniles, aggressive as adults, and they rasp the slime coat off flat-sided fish like angelfish and gouramis.
Siamese algae eater — the only real answer to black beard algae
True SAEs are among the very few animals that eat black beard algae. The problem is identification: a real one has a black stripe running through the tail fin rather than stopping at its base, and no gold sheen above the stripe. If the stripe stops where the tail begins, it is a flying fox.
They reach 15 cm and get lazier about algae as they mature. Use them to clear an existing outbreak, not as a permanent plan — and fix the flow and CO2 instability that caused it, or it returns.
Cherry shrimp — lovely, but not an algae solution
Cherry shrimp graze biofilm and very soft algae, and a mature colony does keep surfaces tidy. But they will not touch hair algae the way amanos do, and they will not touch green spot algae at all. Keep them because they breed readily in our hard water and are beautiful — not for cleaning.
What eats what
- Brown diatom film — otos and nerites (usually resolves on its own as the tank matures).
- Green film on glass — nerites, otos, bristlenose.
- Green spot algae — nerites. Effectively nothing else.
- Hair and thread algae — amano shrimp.
- Black beard algae — true SAE, plus fixing flow and CO2.
- Blue-green slime — nothing. It is cyanobacteria, not algae, and must be dealt with directly.
- Green water — nothing here. Free-floating algae needs a different approach.
The UAE-specific bits
Hard water is a gift. Snails and shrimp build shells and exoskeletons from carbonates, and our tap water supplies the raw material free.
Summer heat is the risk. Warm water holds less oxygen, and invertebrates and otos show it first — before the fish look distressed at all. Past 30 °C your crew is under strain, and cooling the tank outranks everything in this article.
Copper is fatal to invertebrates. Many disease treatments, ich medications especially, contain copper. Check the label — an ordinary course will wipe out your entire crew.
Before you buy
- Wait for the tank to mature. Nothing here belongs in a tank under two months old. There is not enough for them to eat.
- Count them as fish. A cleanup crew adds bioload and needs the same water changes as everything else.
- Think about the floor. Corydoras need sand — a substrate decision, not a fish decision, and one you cannot reverse later. Our guide to sand, gravel and aquasoil covers how that choice constrains everything above it.
Get the light and the maintenance right, then add a few nerites and a group of amanos. That combination handles most of what a well-run tank throws at you — without anyone ending up with a 40 cm fish they cannot rehome.