Fishless Cycle FAQ: Ammonia Source Timeline Test
Fishless cycling is the humane standard — you grow nitrifying bacteria in a sterile tank using bottled ammonia or pure household ammonia as the food source, then add fish only after the cycle finishes. The Dr Tim’s 4 ppm method is the most reliable protocol, completing in 14-28 days at Singapore tank temperatures. This fishless cycle faq from Gensou Aquascaping at 5 Everton Park covers ammonia sources, dosing, and how to read the test results, and this guide answers the 10 questions Singapore aquarists ask most about fishless cycling.
Why cycle fishless instead of with fish?
Fish-in cycling subjects animals to days of 0.5-2 ppm ammonia and 2-5 ppm nitrite — both cause gill burns. Fishless cycling lets you push to 4 ppm ammonia for fast bacterial growth without harming anything. Fishless also lets you stock the tank fully on day one of the cycle’s end, instead of staggering over months.
What ammonia source do I use?
Pure household ammonia from any supermarket — must be fragrance and surfactant free. Shake the bottle: foam means it has detergents. Otherwise, Dr Tim’s Ammonium Chloride is the cleanest dose-by-drops option at SGD 25-35. Avoid “lemon-scented” or “industrial-grade” products. Browse water care for current cycling kits.
How much ammonia do I add?
Target 2 ppm initially using the Dr Tim’s drop chart, or roughly 4-5 drops per 40 litres of pure 9.5 per cent ammonia. Test 30 minutes after dosing and confirm 2 ppm. Older guides recommend 4 ppm but this often stalls the nitrite-eating bacteria phase, so 2 ppm is the modern consensus.
Do I need a bacteria starter?
Strongly recommended. Dr Tim’s One and Only contains live Nitrospira and cuts cycling time from 28 days to 7-14. Tetra SafeStart is similar at lower price. Fluval Cycle and API Quick Start are weaker but still useful as boosters. Refrigerate after opening, use before expiry. Without starter, expect a 21-35 day cycle.
What is the day-by-day schedule?
Day 1: dose to 2 ppm, add bacteria starter. Day 2-7: ammonia drops slowly, nitrite begins to appear. Day 8-14: ammonia hits zero in 24 hours, nitrite peaks at 2-5 ppm. Day 15-21: nitrite drops, nitrate climbs. Day 22-28: both ammonia and nitrite drop to zero within 24 hours of redosing — cycle complete.
How often should I redose ammonia?
Only after both ammonia and nitrite read zero. Premature redosing during the nitrite-spike phase causes nitrite to climb past 5 ppm, which inhibits the very bacteria you are growing. Test daily, redose on the days the test reads clean. Do not maintain a constant ammonia level.
What temperature speeds up the cycle?
28-30°C is optimal — exactly the Singapore ambient most tanks sit at without a heater. Nitrospira doubles every 16-24 hours at 30°C versus 36-48 hours at 22°C. If you have a heater, set 30°C during cycling and drop to species-target after stocking.
Should I run lights and CO2 during cycling?
Lights low (4-6 hours) to limit early algae blooms; CO2 off until cycle is complete. Plants can be added on day one — they will not slow the cycle and may pre-establish before livestock. Heavy filter equipment should run 24/7 throughout to oxygenate the bacteria colony.
What if cycle stalls past day 28?
Check pH first. Below 6.4, nitrification halts. Singapore tap rarely runs that low except in heavy-aquasoil tanks where pH can drop to 5.8-6.2 during the active leaching phase. Do a 50 per cent water change with conditioned tap to raise pH, then redose ammonia and ride it out another 7-10 days.
How do I confirm the cycle is finished?
Three consecutive days where dosing 2 ppm ammonia results in 0 ppm ammonia and 0 ppm nitrite within 24 hours. Nitrate will read 30-80 ppm — that is correct. Do a 75 per cent water change to reset nitrate, then add fish in batches over the next 14 days.
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