V. POND MANAGEMENT & CARE – NURSERY ENVIRONMENT (PHASE 1)

I. Phase 1: Nursery Stage (Vèo Stage)

1. Nursery duration

  • Nursery in ponds < 500 m²: 15–25 days

  • Nursery in ponds > 500 m²: 25–35 days

 

2. Water Quality Management

a. Daily Monitoring

During the nursery phase, farmers must monitor water parameters regularly:

  • pH, alkalinity, temperature → 2 times/day (7:00 & 15:00)

  • Toxic gases (NH₃, NO₂) → at least once/day

  • Minerals (Ca, Mg, K, Fe) → once/day or weekly depending on indicator

REQUIRED WATER QUALITY PARAMETERS

ParameterOptimal ValueChecking FrequencyNotes
pH7.8 – 8.2≥ 2 times/dayStrict requirement
Alkalinity100 – 120 mg/L≥ 2 times/dayStrict requirement
Salinity>5‰≥ 1 time/dayStrict requirement
Dissolved Oxygen>5 mg/L≥ 1 time/dayStrict requirement
NH₃<0.02 ppm≥ 1 time/dayDepends on pH
NO₂<0.5 ppm≥ 1 time/dayDepends on salinity
H₂S<0.03 ppmEvery 5 daysDepends on pH
Calcium>60 mg/L≥ 1 time/dayDepends on salinity
Magnesium>200 mg/L≥ 1 time/dayDepends on salinity
Potassium>55 mg/LEvery 5 daysDepends on salinity
Iron (Fe)<0.1 ppmEvery 5 daysStrict requirement
Temperature28–32°C≥ 2 times/dayStrict requirement

 

b. Adjustments for Abnormal Water Quality

Farmers must observe and correct abnormalities immediately.

WATER PARAMETER CORRECTION GUIDE (per 500 m³)

ParameterAbnormalityTreatment MethodDosageTiming
pH



 		High

 		Ferment 250 g Bacillus subtilis 1090 + 2 kg molasses + 20 L water (4–6h)—9 AM or 3 PM
OR SITTO EM1 L 
OR SITTO TAKE OFF0.3 L 
Low
 		CaO lime2–3 kg9 AM or 3 PM
OR ULTRA-GREEN1 kg 
Alkalinity

 		Low

 		CaO + Dolomite2–3 kg9 AM or 3 PM
OR ALK-BALANCE2–3 kg 
OR ULTRA-GREEN1 kg 
Salinity
 		Low
 		Salt granules200–300 kg9 AM or 3 PM
OR SEA-MINER2–3 kg 
Dissolved OxygenLowIncrease aeration & bottom diffusion——
NH₃

 		High

 		Bacillus subtilis 1090250 g9 AM or 3 PM
OR RHODO BACCIL1 L 
OR SITTO YUCCA0.3 L 
NO₂
 		High
 		RHODO BACCIL1 L9 AM or 3 PM
+ Add clean water (no toxins)——
H₂S

 		High

 		Bacillus subtilis 1090250 g9 AM or 3 PM
OR RHODO BACCIL1 L 
OR SITTO YUCCA0.3 L 
Minerals
 		Low
 		SEA-MINER2–3 kg9 AM or 3 PM
OR SITTO KALI-PHAST2–3 kg 
Iron (Fe)
 		High
 		SITTO POND MAGIC1 kg9 AM or 3 PM
OR SITTO TAKE OFF0.3 L 
Temperature
 		HighReduce feeding; increase aeration; avoid stratification——
LowReduce feeding; increase aeration——

 

3. Feed & Feeding Management

a. Feed

  • Use high-quality, nutrient-rich, easily digestible feed from reputable brands.

  • Choose feed size based on shrimp eye size (“mắt tôm”).

 

b. Feeding Schedule

Based on 100,000 PL12, feed 5 meals/day:

MealTimeAmount
106:3050 g
209:3050 g
312:3050 g
415:3050 g
518:3050 g
Total: 250 g/day  

Feed increments:

  • First 5 days: +100 g/day

  • Next 5 days: +200 g/day

  • Days 11–15: +300 g/day

When shrimp can eat floating pellet No.2, mix additives:

MealAdditives (per kg feed)
1SITTO MIX 5 g + VIVAX 2 ml
2SITTO VIZYM 5 g + SITTO LIVER DETOX L 5 ml
3VIVAX 2 ml + SITTO C-SPARK 5 g
4SITTO BERLAA 5 g + SITTO LIVER DETOX L 5 ml
5D-MAX SHRIMP 5 ml + SITTO VIZYM 5 g

Checking feed consumption:

  • Use feeding trays.

  • Use hand nets to check bottom waste.

  • Siphon-check after 1 week.

Principle: Small – Sufficient – Even – On time.
Do NOT allow leftover feed. Adjust immediately if detected.

 

4. Use of Probiotics & Disinfectants

PROBIOTICS
ProductFunctionDosageApplication
Bacillus subtilis 1090Color water, decompose organics, reduce NH₃ & H₂S250 g / 500 m³9 AM or 3 PM, every 2–3 days
SITTO LBBInhibits pathogens, controls foam, water slime, cuts algae100 g / 500 m³9 AM or 3 PM, every 2–3 days
SITTOZYMECleans pond bottom & liner slime100 g / 500 m³9 AM or 3 PM, every 3–5 days
SITTO EMDisinfects water, stabilizes pond environment1 L / 500 m³9 AM or 3 PM, every 2–3 days
RHODO BACCILRapid bottom cleaning, balances pH, improves DO1 L / 500 m³9 AM or 3 PM, every 2–3 days
SITTO VIZYMPrevents white feces, improves gut health5 g/kg feedTwice daily
DISINFECTANTS
ProductFunctionDosageApplication
SITTO-IODINE COMPLEXWater sterilization, pathogen prevention200 ml / 500 m³Evening 18–20h, every 7–10 days
WANWAYUltra-strong rapid disinfectant200 ml / 500 m³Morning 8–10h, every 2–3 days

 

5. Shrimp Health Management

a. Daily observation

  • Active swimming, strong feeding behavior, clean feces.

  • Check pond bottom via trays: feces, dead shrimp, bubbles.

b. Routine disease screening

  • Examine hepatopancreas, gut, gills under microscope.

  • Send samples for lab diagnostics when abnormalities appear.

c. Handling health issues

  • Maintain alkalinity ≥120 mg/L and minerals via: SEA-MINER 2–3 kg / 500 m³ (daily or every 1–2 days)

  • For curved body or muscle opacity: SITTO KALI-PHAST 1–2 kg / 500 m³ (every 5–7 days)

  • For organic waste decomposition: SITTO THIO 5000 – 1–2 L / 500 m³ (every 5–7 days)

  • For foam or water slime: SIREN – 1 L / 500 m³ (every 3–5 days)

  • For liner slime or fungal spots: SITTOZYME – 100 g / 500 m³ (every 3–5 days)

  • For water refilling: Use water from settling pond treated with Chlorine 30 kg/1,000 m³, ensure no residue.

 

6. Aeration, Water Top-up, Water Exchange, and Siphoning

  • Use both bottom aeration and paddlewheels, positioned evenly.

  • Maintain an oval water flow to avoid dead corners and push waste to siphon pit.

Aeration schedule by shrimp age

AgeAeration Time
<20 days6–8 hours/day
20–40 days12–18 hours/day

Siphoning

  • Siphon once per day (morning or afternoon), starting from day 7–10.

Water top-up & exchange

  • Always top-up or exchange water in the cool afternoon.

AgeWater Exchange
<15 daysTop-up only
>15 days10% per day
>30 days15% per day