Common Beginner Mistakes
Part 5: Common Beginner Mistakes (And Easy Fixes) 5 min Good news: once your tank is running, maintenance is simple. The goal is to keep water clean and fish healthy — without making it tiring. 1) Adding too many fish too fast Why it’s a problem A new tank needs time to grow “good bacteria.” Too many fish too soon = water becomes unsafe. Easy fix Start small Add fish in batches Wait 5–7 days before adding more 2) Skipping anti-chlorine (water conditioner) Why it’s a problem Tap water can harm fish and kill good bacteria. Easy fix Every time you add tap water, add anti-chlorine.No exceptions. 3) Overfeeding Why it’s a problem Extra food rots and creates waste fast. This is one of the fastest ways to ruin water. Easy fix Feed only what fish finish in 15 seconds (rule of thumb) If in doubt, feed less Beginner rule: Slightly hungry fish are safer than overfed fish. 4) Turning off the filter for long periods Why it’s a problem Your filter is the tank’s “engine” and home for good bacteria. If it’s off too long, bacteria can weaken. Easy fix Keep filter running 24/7 Only switch off during maintenance, then turn it back on quickly 5) Washing filter media under tap water Why it’s a problem Tap water can kill the good bacteria living in your filter. Easy fix Rinse sponge/media using old tank water (from your water change bucket) Gentle squeeze only — don’t scrub until “super clean” 6) Keeping lights on too long Why it’s a problem Too much light often leads to algae. Easy fix (simple timing) With plants: 6–8 hours/day Mostly fish: 4–6 hours/day Best upgrade: use a timer 7) Not doing water changes because the water “looks clear” Why it’s a problem Clear water can still have invisible waste building up. Easy fix Stick to the easy routine: 20–30% water change once a week 8) Changing too many things at once Why it’s a problem Big sudden changes can stress fish and make the tank unstable. Easy fix Change one thing at a time: Adjust feeding first Then water change Then filter cleaning (if needed) Quick “Troubleshooting” Cheat Sheet (Diagram) Cloudy water Reduce feeding + do 20–30% water change + keep filter on + add beneficial bacteria Algae growing fast Shorten light hours + avoid direct sunlight + weekly water change Fish not active / hiding Test water (ammonia/nitrite) + check temperature + check flow If you tell our That Aquarium staff what you’re unsure of, we’ll be sure to help wherever we can! Next Up: We’ll go over some fish recommendations for beginners! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
Easy Feeding Guide
Part 8: Easy Feeding Guide (Healthy Fish + Clean Water) 5 min Feeding is simple — and it’s one of the biggest reasons tanks stay clean (or get messy). Follow these easy rules and you’ll avoid most beginner problems. 1) The #1 Feeding Rule (Most important) ✅ Feed small amounts Only feed what your fish can finish in 15 seconds. If food is left floating or sinking after that = you fed too much. 2) How Often Should You Feed? Most community fish (guppies, platies, rasboras, tetras) 1–2 times a day Small portions only Bottom fish (Corydoras, etc.) Feed at night or after lights off (they are more active) Use sinking food, small amounts Betta Once a day is usually enough Small portions (bettas are easy to overfeed) Beginner tip:If you’re unsure, once a day is a safe start. 3) Best Beginner Foods (Simple choices) A) Main daily food (choose 1) Quality flakes (easy for small community fish) Micro pellets (cleaner than flakes, less mess) Highly recommend Slow Sinking Betta pellets (for bettas) B) Add-on foods (optional, for variety) Frozen food (example: bloodworms/brine shrimp) — 1–2 times/week Live food (if you like) — optional, not necessary for beginners Simple tip:A good pellet/flakes as the main food is already enough for beginners. 4) How Much to Feed (Easy guide) For a small group of fish Start with a tiny pinch (or a small scoop) Watch them eat Adjust next feeding based on leftover food If you see food sinking to the bottom Stop feeding. Leftover food is a fast way to dirty the water. 5) Common Feeding Mistakes (And quick fixes) Mistake: “My fish look hungry, so I keep feeding” ✅ Fix: Fish often beg even when they’re full. Stick to the 15 seconds rule. Mistake: Feeding too many types of food every day ✅ Fix: Keep it simple. 1 main food + optional treat once in a while. Mistake: Not removing leftover food ✅ Fix: If you accidentally overfeed, remove leftovers with a net and do a small water change. 6) Signs You’re Feeding Too Much Water turns cloudy Bad smell Algae grows faster Fish poop a lot and tank floor looks dirty Fish look bloated ✅ Simple fix: Feed less Do a 20–30% water change Siphon the tank floor lightly 7) Easy Weekly Feeding Routine (Beginner-friendly!) Mon–Sat: Normal feeding (small) 1 day a week: Light feeding OR skip feeding(This helps reduce waste and keeps water cleaner.) Skipping 1 day is safe for most healthy fish. If you tell our That Aquarium staff what fish you plan to stock, we can help you pick out the best option for your fish! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
Easy Plant Guide
Part 7: Easy Plant Guide (No Stress, Beginner-Friendly) 5 min Plants make your aquarium look more natural, help with water quality, and make fish feel safer. The best part? You can do it without complicated setups. 1) Why plants are good (simple reasons) Make the tank look nicer Fish feel less stressed (more hiding space) Helps absorb some waste in the water Makes the tank feel more “alive” 2) The 3 Plant Types (So you know what to do) A) “Attach plants” (easiest) These plants should NOT be buried in the substrate. Examples: Anubias Java Fern Moss (Java Moss / Christmas Moss) ✅ Best for beginners How to use: Tie or wedge them onto wood / rock / decor (Usually sell in tied woods) Keep the “root base” above the substrate B) Rooted plants (go into the substrate) These plants like their roots in gravel/soil. Examples: Cryptocoryne (Crypts) Amazon Sword Vallisneria Water Wisteria (Hygrophila difformis) How to plant: Push roots into substrate gently (video) Don’t bury the plant too deep (let the leaves stay above) C) Floating plants (super beginner-friendly) These sit on the water surface. Examples: Amazon Frogbit Red Root Floater Salvinia Dwarf Water Lettuce Water Sprite (floating) ✅ Great for beginners✅ Helps reduce algae by blocking extra light✅ Fish feel safer under them 3) Beginner “Plant Layout” (Easy placement) Front (short plants / open space) Keep it open for viewing and easy cleaning You can leave it empty or add moss/low plants Middle (main focus area) Anubias on rock/wood Java Fern tied to decor Back (taller plants) Vallisneria (great background) Water Wisteria (fills space fast) Simple goal:Front open + middle nice + back tall = looks natural and clean. 4) Light for plants (simple timing) With plants: 6–8 hours/day Start lower first (especially for new tanks) to reduce algae Use a timer if possible (easy and consistent) 5) How to plant without killing plants (common mistakes) ✅ Do this Rinse plants gently (remove dirt/snails if needed) Plant slowly, don’t rush Give plants time to adapt (some “melt” is normal) ❌ Don’t do this Don’t bury Anubias / Java Fern root base Don’t blast light 10–12 hours a day Don’t keep changing the setup every few days 6) “Plant melt” (normal beginner worry) Some plants may look worse in the first 1–2 weeks. This can be normal while they adapt. What to do: Keep light steady Don’t overfeed Continue weekly water changes Give it time 7) Super Easy Plant Pack (Beginner Starter Set) If you want a simple “safe mix”: 1–2 Anubias 1–2 Java Fern 1 moss (Java/Christmas) 1 Vallisneria (background) 1 Water Wisteria (fills space) 1 floating plant (Amazon Frogbit or Salvinia) This combo looks good, grows well, and is beginner-friendly. If you tell our That Aquarium staff what fish you plan to stock, we can help recommend if it’s beginner-safe! Next Up: We’ll go over some feeding tips for your fish to keep them healthy! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
Tank Cycling
Part 3: Start Safely (Cycling Made Simple) + When to Add Fish 5 min A new tank needs time to become stable. Don’t worry — you don’t need to be “pro.” Just follow this simple plan. What is “Cycling”? Cycling means growing the good bacteria in your filter. These bacteria help handle fish waste, so your water stays safe. No bacteria = water can turn unsafe fast.Enough bacteria = tank becomes stable and easy. The 2 Safe Ways to Start (Choose 1) Option A (Best & easiest): Cycle first, then add fish This is the safest route for beginners. Simple steps: Set up tank (water + anti-chlorine) Turn on filter 24/7 Add beneficial bacteria bottle (as directed) Let it run and “mature” for a short period Test the water before adding fish ✅ Less stress✅ Fewer fish problems✅ More success Option B (If you really want fish earlier): Add fish slowly (small amount only) If you add fish too fast in a new tank, the tank can’t “handle” the waste yet. Safe rule:Start with a small number of hardy fish, not a full tank. ✅ Add few fish first✅ Monitor water✅ Slowly increase over time How Long Should a New Tank Run Before Fish? For a smoother start: Recommended: about 2–4 weeks With bacteria bottle + proper filter running, many tanks start more smoothly — but still don’t rush to add too many fish. When is it Safe to Add Fish? ✅ Safe signs Filter has been running daily (24/7) You are using anti-chlorine correctly You added beneficial bacteria consistently Water looks clear and doesn’t smell “bad” Your test kit shows the water is in a safe range Best simple test kit focus: Ammonia, 0 ppm Nitrite 0 ppm If these are not okay, wait and continue the steps below. The #1 Beginner Mistake (Avoid this) ❌ Adding too many fish too fast Even if the tank looks clear, the water can still be unsafe. Simple rule:Add fish slowly. Your tank will stay easy. Best Beginner Fish to Start With (Hardy + calm) Platies Guppies Mollies Harlequin Rasboras If you want a single fish tank: 1 male Betta (gentle flow + hiding spots) Quick “Do & Don’t” for Success ✅ DO Keep filter on 24/7 Use anti-chlorine every time Feed small amounts Add fish slowly ❌ DON’T Wash filter media under tap water Overfeed (leftover food = water problem fast) Add a full tank of fish on day 1 Beginner “Week-by-Week” Plan Week 1: Set up & build the base Anti-chlorine every time you add water Filter on 24/7 Add beneficial bacteria (follow bottle) Light: keep it simple (4–6 hours/day) Week 2: Keep it stable Continue beneficial bacteria Do small water changes if needed Keep feeding low if you already have fish (don’t overfeed) Week 3–4: Start adding fish (slowly) Add fish in small batches Wait a few days to 1 week between adding more fish Keep checking water https://youtu.be/p1NfPpF0T1E If you tell our That Aquarium staff what you’re unsure of, we’ll be sure to help wherever we can! Next Up: We’ll go over some maintenance basics to keep your tank clean and healthy! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
Care & Maintenence
Part 4: Care & Maintenance 5 min Good news: once your tank is running, maintenance is simple. The goal is to keep water clean and fish healthy — without making it tiring. 1) Weekly Routine (Beginner Easy Schedule) ✅ Every day (2–3 minutes) Check fish: are they active and eating? Quick look at water: clear? any smell? Feed small amount (only what they finish in 1–2 minutes) Simple rule: Less food is safer than more food. ✅ Once a week (15–25 minutes) Do a water change 20–30% is perfect for most beginner tanks Also do: Light wipe the glass if needed Siphon some dirt from the tank floor (not everything ✅ Once a month (10 minutes) Check filter flow If water flow becomes weak, it’s time to clean the filter sponge/media (simple steps below). 2) Water Change (Step-by-step) What you need Siphon hose Bucket Anti-chlorine Steps Switch off filter (and heater if you have one) Use siphon to remove 20–30% water Add anti-chlorine (for the new water) Add back tap water Switch filter back on ✅ Done. Important:Always treat the new water with anti-chlorine. Don’t skip this. https://thataquarium.com/wp-content/uploads/2026/03/aquarium-maintenance-1.mp4 3) How Often Should You Change Water? For most beginner tanks: 20–30% once a week is the safe default If your tank is crowded or you feed a lot: 30–40% once a week (or split into 2 smaller changes) If your tank is lightly stocked and stable: 20% once a week still keeps it easy and safe 4) Filter Care (Very important!) Your filter is home to the good bacteria. So we clean it gently. When to clean the filter Flow becomes weak Filter looks clogged Usually every 2–4 weeks (depends on tank) How to clean it (the safe way) ✅ Use tank water (from your water change bucket)✅ Gently squeeze/rinse the sponge/media❌ Do NOT wash with tap water❌ Do NOT scrub until “perfect clean” Simple goal: Clean enough to restore flow, not “make it brand new.” https://thataquarium.com/wp-content/uploads/2025/05/cleanfilter-compressed.mp4 5) Light Timing (Avoid algae, keep tank pretty) With plants: 6–8 hours/day Mostly fish / few plants: 4–6 hours/day Tip: A timer makes everything easier. 6) Algae Control (Beginner-friendly) Algae is normal. It becomes a problem only when it grows too much. Easy ways to control algae Don’t overfeed Don’t leave the light on too long Do weekly water changes Keep tank away from direct sunlight 7) “Something feels off” Quick Fix Guide Water looks cloudy Reduce feeding Do a 20–30% water change Make sure filter is running 24/7 Fish look stressed / hiding Check if filter flow is too strong Test water (ammonia/nitrite) Bad smell Do a water change Siphon waste from the bottom Check for leftover food If you tell our That Aquarium staff what you’re unsure of, we’ll be sure to help wherever we can! Next Up: We’ll go over some common beginner mistakes! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
The Basics
Part 2 – The Basics! 5 min Before you add fish, you only need to understand 3 core things: Anti-chlorine Good bacteria Filter + Light Once you get these right, aquarium keeping becomes easy. 1) Anti-Chlorine (Water Conditioner) — “Make tap water safe” What it is Tap water has chlorine/chloramine. These can harm fish and also kill the good bacteria your tank needs. Anti-chlorine makes tap water safe instantly. When to use it ✅ Every time you add new tap water, including: First tank setup Every water change Top up water Simple rule New water in = anti-chlorine in (same time/or first). 2) Beneficial Bacteria — “The good helpers that keep water safe” What it is Beneficial bacteria are good microbes that live mainly in your filter.They help break down fish waste so your water stays safer. Think of them like your tank’s clean-up team. Why beginners need this In a new tank, these bacteria are not there yet.That’s why new tanks can have water issues at the start. How to use bacteria bottle Add it when you set up the tank Add again for the first few weeks Add again after big water changes Follow the dose on the bottle Important: Good bacteria need a running filter and oxygen to grow well. 3) Filter — “The engine of your aquarium” What it is A filter helps in 3 simple ways: Catches dirt (leftover food, waste) Moves water (keeps oxygen levels better) Houses good bacteria (this is the big one) Beginner tip If you want an easy tank, don’t switch off your filter. Keep it running 24/7 Only off during maintenance (and not for too long) Common beginner-friendly filters Sponge filter (simple, stable, easy) hyperlink to the webpage, on how to use it Hang-on-back filter (HOB) (easy and clean look) hyperlink to the webpage, on how to use it Internal Filter (easy, plug and play) hyperlink to the webpage, on how to use it 4) Light — “For nice viewing + for plants” What it is A good light: Makes your fish look more colourful Makes the tank look clean and lively Helps plants grow (if you have plants) How long to turn on the light To avoid algae, don’t overdo it: With plants: 6–8 hours/day Mostly fish / few plants: 4–6 hours/day Best beginner move: Use a timer (so you don’t forget). Super Simple Setup Flow (1 minute version) Add anti-chlorine Fill tank with tap water Start filter (and air pump if needed) Add beneficial bacteria Turn on light (short hours at first) If you tell our That Aquarium staff what you’re unsure of, we’ll be sure to help wherever we can! Next Up: We’ll go over how to cycle your tank before adding in your fish! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
Simple Fish Selection Guide (Easy + Beginner Safe)
Part 6: Simple Fish Selection Guide 5 min Choosing the right fish is one of the best ways to make aquarium keeping easy. This guide helps you pick fish that are peaceful, hardy, and beginner-friendly. 1) Start With These 3 Easy Rules ✅ Rule 1: Match fish to your tank size Smaller tank = fewer fish.More space = more stable water = easier success. ✅ Rule 2: Pick peaceful fish Peaceful fish fight less, stress less, and stay healthier. ✅ Rule 3: Add fish slowly Don’t add everything at once.Add in small batches and let the tank adjust. 2) Beginner-Friendly Fish (Good First Choices) Top easy community fish Harlequin Rasboras (very stable, peaceful) Guppies (colourful, active) Platies (hardy, friendly) Mollies (hardy, slightly bigger) Corydoras (bottom fish, peaceful) If you want a single “main fish” 1 male Betta (solo tank, gentle flow, needs hiding spots) 3) Tank Size → Simple Fish Suggestions 1ft tank (small setup) Best for: 1 male Betta Optional: small clean-up (depends on setup)Keep it simple. Small tanks change fast, so don’t overcrowd. Easy combo: 1 Betta + easy plants (Anubias/Java Fern) + floating plants 2ft tank (best beginner size) This is the “sweet spot” for beginners. Easy community combo ideas: Option A (super stable):8–12 Harlequin Rasboras + 6 Corydoras Option B (colourful):6–10 Platies or Guppies (choose one type to start) 4) Easy “Safe Combos” (Beginner Approved) Combo 1: Calm & classic Harlequin Rasboras + CorydorasPeaceful, stable, low drama. Combo 2: Colourful & fun Guppies or Platies (start with one type)Simple feeding, hardy fish. Combo 3: Low-stress Betta setup 1 male Betta + plants + floating plantsBeautiful and simple. 5) What to Avoid (Common beginner trap fish) Some fish are popular, but not beginner-easy because they: grow too big are aggressive need special water conditions create lots of waste Avoid as a first tank (unless you already know what you’re doing): Very large fish Very aggressive fish Fish that need “perfect” water from day one If you tell our That Aquarium staff what fish you plan to stock, we can help recommend if it’s beginner-safe! Next Up: We’ll go over some easy hardy plants for beginners! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page:
The Essentials
Quick And Easy Guide for Beginners! 5 min Not Sure where to start? We’ve prepared a quick start guide to start your very own tank! This is a more basics only guide compared to our other beginner guide, so head on over there if you want more in-depth explanations into things! The Must-Have Items (Don’t Skip these!) Tank (Aquarium) Pick a size you can manage. Bigger tanks are usually more stable (easier for beginners), but choose what fits your space. Beginner sweet spot: 1ft tank (about 30cm) for a comfortable start Filter (Keeps water clean) Your filter is like the “heart” of the tank. It keeps the water safe for fish. Beginner picks (easy + reliable): Sponge filter (simple, low cost, beginner-friendly) Hang-on-back filter (HOB) (easy to use, good flow) Air Pump + Air Tube (If using sponge filter) Your filter is like the “heart” of the tank. It keeps the water safe for fish. Beginner picks (easy + reliable): Sponge filter (simple, low cost, beginner-friendly) Hang-on-back filter (HOB) (easy to use, good flow) Needed to run a sponge filter. Also helps keep oxygen levels strong. Light (Makes the tank look nice + helps plants grow) Tap water has chlorine/chloramine. This protects your fish. You must use it every time you add new tap water. Water Conditioner (Very important) A good aquarium light does two things: Makes your fish look more colourful and the tank more “alive” Supports plant growth (if you keep plants) Beneficial Bacteria Bottle (Helps your tank start safer) This is a bottled “good bacteria” product that helps your tank build a healthy filter system faster. Why it’s useful for beginners: Helps reduce early water problems Supports a smoother start while your tank is new Works best when you’re running your filter properly Substrate (Gravel / Sand / Soil) This is the “floor” of your tank. Beginner options: Gravel (easy, clean, low maintenance) Sand (nice look, but needs slightly more care) Aquasoil (best for plants, but can be more “active” for beginners) If you want easy plants without stress: Gravel + root tabs (optional) is a simple combo. A Net + Siphon (For cleaning) Net: to move fish safely Siphon hose: makes water change easy and fast Basic decor (Optional, but nice) Small rocks / driftwood / hiding placesFish feel safer when they have shelter. Test Kit (So you don’t guess) (Optional) as at That Aquarium we conduct free water testing for your aquarium! This helps you know if your water is safe. At minimum, test: Ammonia Nitrite Nitrate Beginner Plant Recommendations (Easy, hardy, low stress) These plants are beginner-friendly and don’t need CO₂. Easiest plants to start with: Anubias (slow growing, very hardy) Java Fern (easy, doesn’t need soil) Java Moss (good for shrimp and baby fish) Cryptocoryne (Crypts) (nice leaves, beginner friendly once settled) Vallisneria (fast grower, good “background” plant) Hornwort (can float too) Duckweed (very fast-growing — use only if you’re okay with it spreading) Red Root Floater Simple planting tip (important): Anubias + Java Fern: don’t bury the “root base” (rhizome).Tie or wedge onto wood/rock instead. Beginner Plant Recommendations (Easy, hardy, low stress) These plants are beginner-friendly and don’t need CO₂. Easiest plants to start with: Anubias (slow growing, very hardy) Java Fern (easy, doesn’t need soil) Java Moss (good for shrimp and baby fish) Cryptocoryne (Crypts) (nice leaves, beginner friendly once settled) Vallisneria (fast grower, good “background” plant) Hornwort (can float too) Duckweed (very fast-growing — use only if you’re okay with it spreading) Red Root Floater Simple planting tip (important): Anubias + Java Fern: don’t bury the “root base” (rhizome).Tie or wedge onto wood/rock instead. Beginner Fish Recommendations (Hardy + peaceful) If you’re brand new, start with fish that are forgiving and calm. Best beginner community fish: Endler Guppies (colourful, active) Platies (hardy, peaceful) Mollies (hardy, a bit bigger) Neon / Cardinal Tetras (best after tank is stable) Harlequin Rasboras (very stable community fish) Rummy Nose Tetra Colour Tetra Zebra Danios Corydoras (bottom cleaner, peaceful) If you want just 1 fish: Betta (1 male only)Great for smaller setups with gentle flow + hiding spots. Beginner “Safe” Fish Combos (Easy examples) Option A: Simple 2ft community tank 8–12 Harlequin Rasboras 6 Corydoras Easy plants (Anubias, Java Fern) Option B: Livebearer tank (colourful + easy) 6–10 Guppies or Platies Some moss / Vallisneria Easy plants (Anubias, Java Fern) Option C: Betta tank (peaceful solo tank) 1 male Betta Anubias + Java Fern + hiding cave(non Sharps objects) Quick Note Before You Buy Fish A brand new tank needs time to become safe (this is the “cycling” stage). Don’t worry — we’ll keep it simple in Part 2. Next Up: We’ll go over some basics before adding fish! Author: Kelvin Phua Illustrator(s): Rong Sheng >>Next Page: