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BFS-014 · Tide & Drain Council · May 2026

Tide Calendar, Weather & Drain Plan
Paombong, Bulacan

Lessee exit · Pond prep · Lablab or Fingerling decision

🌊
SPRING TIDE: May 22 start · 2 × 24" gates + 4DR5 pump — Low tide May 22 at 10:44 PM (−0.17 m). Combined gate flow ~3,000 m³/hr. Two evening drain sessions (May 22–23) + pump removes majority of 54,000 m³ pond. No teaseed needed — lessee doing cleanout. Next spring tide June 4–8 (morning lows, different schedule).
✓ OPTIMAL TIMING
Today
May 15
2026 · Farm prep starts
Drain Start
May 22
23 max · lessee cleanout done
Spring Tide Peak
May 19–21
Low: −0.37 m (May 19)
Habagat Onset
Late May
El Niño may delay
Target Stocking
July 9
BFS-012 schedule
🌊 Interactive Tide Chart — Manila Bay / Paombong

Tide Height Chart — Drag slider to navigate

Drain zone (<0 m) Dike alert (>1.2 m) Normal water
May 22 PST
Cursor Time—
Tide Height—
Gate Status—
Phase—
📋 Tide Reference Table — Key Events (May 15 – June 15)
Date High Tide Low Tide (Evening/AM) Phase Gate / Drain Notes
May 15 (Fri)
TODAY		 ~9:00 AM · +0.90 m ~3:30 PM · −0.05 m Spring building OPEN ~2–6 PM (small window)
May 16 (Sat) 8:52 AM · +1.09 m 4:51 PM · −0.14 m Spring OPEN 3–8 PM
May 17 (Sun) 9:23 AM · +1.25 m 5:49 PM · −0.27 m Spring OPEN 4–9 PM · Good drain
May 18 (Mon) 10:01 AM · +1.38 m 6:47 PM · −0.35 m Spring OPEN 5–10 PM · Great drain
May 19 (Tue)
⭐ SPRING PEAK		 10:44 AM · +1.46 m 7:46 PM · −0.37 m Peak Spring OPEN 5:30–11 PM · Best of month
May 20 (Wed)
Peak high		 11:32 AM · +1.47 m 8:48 PM · −0.34 m Peak Spring OPEN 6:30 PM–midnight
May 21 (Thu)
🔑 LESSEE OUT		 12:23 PM · +1.42 m 9:49 PM · −0.27 m DRAIN START OPEN 7 PM–1 AM · Start tonight!
May 22 (Fri) 1:18 PM · +1.31 m 10:44 PM · −0.17 m Drain D2 OPEN 8 PM–2 AM
May 23 (Sat) 2:16 PM · +1.16 m 11:29 PM · −0.06 m Drain D3 OPEN 9 PM–3 AM · Last good spring
May 24 (Sun) ~3:10 PM · +0.98 m ~12:15 AM · +0.05 m Weakening Barely drains · Start bottom work
May 25–28 +0.58–0.79 m +0.12–0.42 m NEAP CLOSED · No drainage · Bottom work only
May 29–31 +0.62–0.84 m +0.11–0.38 m Recovering Minor exchange only · Continue prep
Jun 1–3 +0.97–1.22 m −0.08 to −0.16 m Spring building OPEN from Jun 2 PM · Refill begins
Jun 4–8
⭐ NEXT SPRING		 +1.30–1.43 m −0.24 to −0.31 m Spring OPEN ~6–10 AM · Morning lows now!
Jun 9–15 +0.65–1.28 m −0.11 to +0.25 m Approaching neap Controlled refill · Fertilizer window
📋 Recommended Drain Plan (Day-by-Day)
1
May 19–20 (if lessee leaves early)
Pre-drain if possible — Peak spring
If lessee is cooperative and exits before May 21, open gate May 19 at ~5:30 PM. Low tide reaches −0.37 m at 7:46 PM — the deepest low of the entire month. Even 1–2 cycles now saves significant pump time later.
Optional bonus
2
May 22 (Evening) — DRAIN START
Open both 24" gates ~8 PM as tide falls
Lessee gone. Open both sluice gates simultaneously at ~8 PM. Low tide: 10:44 PM at −0.17 m. Two 24" gates at this head = ~2,800–3,500 m³/hr combined flow. Run for ~5 hours (8 PM – 1:30 AM) = 14,000–17,500 m³ out — roughly 26–32% of the pond's volume in one night. Close both gates by 2 AM before tide rises. Engage 4DR5 pump on deepest corner pools where gravity can't reach.
Primary drain Spring
3
May 23 (Evening)
Drain Day 2 — Open gates ~9 PM
Low tide: 11:29 PM at −0.06 m. Tidal head is weaker but the pond level dropped overnight so differential pressure is still useful. Open both gates 9 PM–3 AM. Pump runs simultaneously. By end of this session, large areas of the bottom should be exposed. No teaseed needed — lessee already cleaned out. Start applying quicklime to exposed mud as it drains.
Drain D2
4
May 24 (Final drain)
Low tide ~12:15 AM — marginal but pump covers the rest
Low tide: ~12:15 AM at +0.05 m (barely below datum). Gravity drainage minimal — gate only useful if pond level is still significantly above 0. Switch primary effort to 4DR5 pump. By this point the pond should be mostly empty with only corner pools remaining. Continue pumping through the day. Start tilling and lime application on exposed areas.
Pump primary
5
May 24–28 — NEAP PERIOD
Bottom work — lime, tilling, cleanout
Tides too small to drain significantly. Use this window productively: (a) Apply quicklime (CaO) 1,000 kg/ha to exposed bottom. (b) Till it into top 5–10 cm soil. (c) Remove dead fish and debris. (d) Patch any dike cracks before rain season. (e) Pump remaining pools if you have a pump — now is the time.
Neap Bottom work
6
May 29 – June 3 — Recovery
Continue prep · Allow partial controlled refill
Tides recovering toward next spring. Allow some tidal water in to maintain brackish conditions (prevents extreme temperature/drying of bottom). Continue fertilizer base prep. If dry-out is target, keep gates closed and only open briefly for observation. Monitor dikes for seepage as rain begins.
Transition
7
June 4–8 — NEXT SPRING TIDE
⚠️ Morning lows now — schedule changes!
The tidal cycle has shifted. Low tides are now in the morning (6–10 AM) instead of evening. Open gates early morning for final water exchanges. If pond still has too much water, drain again using June 4–7 mornings. If starting refill for lablab: allow water in during PM high tides (10 PM–midnight range), close at dawn.
Spring Morning lows
8
June 9–14
Fertilize · Establish lablab · Monitor salinity
Pond refilled with fresh brackish water. Begin fertilizer program: 16-20-0 at 50 kg/ha (phosphate), then urea (46-0-0) at 30 kg/ha 1 week later. Target salinity 20–30 ppt. If salinity drops below 15 ppt from rain, pause fertilizer and wait. Lablab mat needs 2–3 weeks of sun to establish.
Fertilizer
9
July 9 (Target)
STOCKING DAY
If lablab established: bioassay first (3–5 fingerlings in bucket for 24h). Stock 3–5 cm fingerlings at planned density. If lablab failed due to rain: pivot to feed-based grow-out using 3–5 inch fingerlings at ₱1.2–1.7/piece (see Fingerling Fallback card below).
STOCKING
🧠 Council Analysis — Drag to reorder

Hold and drag any card to rearrange. All recommendations based on BFAR, FAO, and PAGASA data for Paombong / Manila Bay.

⠿
🗓️ May 22 vs May 23 — Which Day to Start Draining?
✓ VERDICT: May 22 — push hard for this
  • May 22 low tide: 10:44 PM at −0.17 m · Spring still decent
  • May 23 low tide: 11:29 PM at −0.06 m · Barely negative — weaker pull
  • May 22: 2 × 24" gates at −0.17 m head = ~2,800–3,500 m³/hr combined. That's ~14,000–17,500 m³ in a 5-hour window = 26–32% of pond volume in one night.
  • May 22 high tide = 1.31 m — close gates firmly by 9 AM, reopen ~8 PM as tide falls
  • May 23 low = −0.06 m. Tidal head is much less. Flow rate drops ~60%. Still ok with pump support, but slower.
  • Gate schedule May 22: Open ~8 PM → peak drain ~10:44 PM → close ~2:30 AM before tide rises
  • 4DR5 pump: Use pump for deepest corner pools after gate drainage. Adds ~40–80 m³/hr continuous. Critical for final 20 cm of water tidal gravity can't reach.
  • No teaseed needed — lessee doing cleanout. Skip straight to quicklime on drained bottom.
⠿
☀️ Can We Expose the Pond Bottom? Weather Reality Check
✗ Full crack-dry is NOT realistic in late May
  • Why it won't fully work: Full crack-dry needs 7–10 consecutive sunny days at 33–36°C. Late May Bulacan = pre-monsoon showers, afternoon thunderstorms every 2–3 days. Even El Niño suppresses rain volume but not frequency.
  • PAGASA Region III forecast (coastal Bulacan): near-normal to above-normal rainfall even in El Niño years for coastal/estuarine zones like Paombong.
  • 6 ha of clay-silt fishpond bottom retains moisture deeply. Exposed areas will re-wet after every rain shower. You will not get crack-dry.
  • BUT — you don't need to. Quicklime (CaO) reacts with wet mud, not dry mud. CaO + H₂O → Ca(OH)₂ + heat. The reaction actually works ON wet substrate. Apply on wet exposed bottom, till in, it sterilizes regardless of sun.
  • What IS achievable (May 22–28): High spots and levee areas dry within 2–3 sunny days. Lower areas stay moist. Apply 1,000 kg/ha quicklime across everything. Till high spots. Let chemistry do the rest.
  • Dike risk from rain: Saturated earthen dikes can slump. During neap/work period, inspect dike crest daily after rain. Pack any crab holes or soft spots immediately. Don't leave gates open unattended during heavy rain.
  • Bottom line: Skip the expectation of full dry-out. Lime on wet bottom = same biosecurity result. You save 2–3 weeks of waiting.
⠿
⚗️ Chemical Options — Teaseed vs Lime vs Others
📋 RECOMMENDED SEQUENCE
  • Step 1 — Kill pest fish (in water): Teaseed cake · 12 g/m³ (if salinity >15 ppt)
  • Saponin kills all finfish; spares shrimp. Degrades in 3–7 days. Locally available ~₱50–80/kg.
  • Alternative: Chlorine (calcium hypochlorite, 65%) at 20–30 g/m³ · nuclear option · kills everything including plankton · wait 7–14 days
  • Rotenone available but restricted-use in PH. Needs BFAR license. Not recommended unless eels are a problem.
  • Step 2 — After draining (on bottom): Quicklime CaO · 1,000 kg/ha
  • Raises soil pH >8 · kills parasites + anaerobic bacteria · apply then till in · wait 1–2 weeks before refill
  • Cost estimate 6 ha: Teaseed ~₱24–40K · Quicklime ~₱60–120K
⠿
🌿 Lablab in Rain — Will It Work?
⚡ CONDITIONAL — El Niño gives a window
  • Lablab needs salinity >15 ppt + sunlight. Heavy rain crashes both.
  • El Niño factor (2026): PAGASA 79% probability El Niño by June–Aug · delays habagat · drier than normal May–June
  • You may get 4–6 weeks of favorable conditions (late May through mid-June) before full wet season
  • If lablab succeeds: 2–3 weeks to establish mat. Start fertilizer by June 10–14.
  • If lablab fails: Shift to lumut (filamentous algae) as natural food OR go straight to commercial feeds
  • Rain management trick: Before heavy rain, raise pond water level to buffer salinity crash. Use overflow boards to release fresh top layer while retaining saltier bottom water.
  • Decision gate: Assess lablab by June 25. If poor mat, trigger fingerling fallback plan.
⠿
🌱 Fertilizer in Rain — 16-20-0 and 46-0-0
⚡ SPLIT DOSE — Don't broadcast in rain
  • 46-0-0 (Urea): Highly water-soluble · washes out within 24–48h of heavy rain · money wasted
  • 16-20-0 (Ammonium phosphate): Phosphate binds to soil better · more resilient to rain · still loses effectiveness if pond is frequently flushed
  • Best practice in rain season: Apply 16-20-0 first (phosphate stays) · apply urea only when 3+ sunny dry days forecast · use smaller more frequent doses
  • Organic alternative: Chicken manure (500–1,000 kg/ha) stays in sediment even during rain · more appropriate for wet season
  • If it rains right after you apply: Close gates temporarily to reduce flushing. Wait for salinity to recover (>15 ppt) before next fertilizer application.
  • Do NOT fertilize if salinity <10 ppt — lablab won't grow anyway and it's wasted
⠿
🐟 Fingerling Order — 40k Alive Per Box at 80% Survival
📌 ORDER MATH — 100k total to get 80k alive
  • Target: 40,000 surviving fish per box × 2 boxes = 80,000 alive at harvest start
  • At 80% survival rate: 40,000 ÷ 0.80 = 50,000 per box to order
  • Total fingerlings to order: 100,000 pieces
    • Box A · order 50,000 pcs—
    Box B · order 50,000 pcs—
    Total @ ₱1.20/pc₱120,000
    Total @ ₱1.70/pc₱170,000
    Survivors (80k) × avg 200g × ₱130/kg~₱2.08M gross
  • 3–5 inch fingerlings (7.5–12.5 cm): skip lablab dependency. Higher survival than fry. Start feeding commercial pellets from Day 1.
  • Extra feed cost vs lablab path: ~₱80–120K per cycle (no free algae phase)
  • If lablab succeeds: Use 3–5 cm fingerlings at lower cost. Lablab covers first 45–60 days of nutrition.
  • If lablab fails: Order 3–5 inch fingerlings (100k total). Decision deadline: June 25.
💰 Financial Comparison — Lablab Delay vs Skip to Feeds (50k/box · 100k total)
Verdict: Lablab pathway saves ₱95,000–₱140,000 per cycle — worth the 3-week delay unless cash flow is urgent or lablab genuinely fails.
Assumptions: 50k stocked per box, 80% survival = 40k alive per box, avg harvest weight 200g, bangus price ₱130/kg, fingerlings ₱1.20/pc. 6 ha total.
Item Pathway A · Lablab
Stock Jul 9 · Harvest Nov 6		 Pathway B · Skip Lablab
Stock Jun 22 · Harvest Oct 20
Fingerlings (100k × ₱1.20) ₱120,000 ₱120,000
Quicklime (6 ha × 1,000 kg × ₱15) ₱90,000 ₱90,000
Fertilizer (16-20-0 + urea × 2 apps) ₱45,000 ₱0 (skip)
Commercial feed ₱310,000
Lablab covers D1-45 (~₱140K savings)		 ₱450,000
Full feeds from Day 1
Labor (caretakers · ~4.5 months) ₱126,000 ₱126,000
Fuel, pump, misc ₱55,000 ₱55,000
TOTAL COST ₱746,000 ₱841,000
Gross Revenue
(80k × 200g × ₱130/kg)		 ₱2,080,000 ₱2,080,000
NET PROFIT ₱1,334,000
Margin: 64%		 ₱1,239,000
Margin: 60%
If fingerlings at ₱1.70/pc (add ₱50,000 to both):
Path A net: ₱1,284,000  |  Path B net: ₱1,189,000  |  Lablab advantage still: ₱95,000/cycle
When to choose Pathway B (skip lablab):
❌ Lablab assessment on Jun 25 shows poor mat growth
⚡ Cash flow urgency — need harvest Oct instead of Nov
⚡ Habagat arrives early (pre-June 10) → salinity crash kills lablab
✓ Even in Pathway B: ₱1.24M profit is still excellent. It's not a losing bet.
📅 Activity Calendar — May 10 to June 30
Pond Prep Timeline · Paombong, Bulacan · May–June 2026
Lessee
Drain
Lime/Bottom
Refill
Fertilize/Lablab
Spring tide
Neap
Sun
Mon
Tue
Wed
Thu
Fri
Sat
May 10
May 11
May 12
May 13
May 14
May 15 ★
TODAY · Farm prep
Spring building
May 16
Lessee in pondSpring
Low 4:51PM −0.14m
May 17
Lessee in pondSpring
Low 5:49PM −0.27m
May 18
Lessee in pondSpring
Low 6:47PM −0.35m
May 19 ⭐
Lessee in pondPEAK SPRING
Low 7:46PM −0.37m
May 20
Lessee in pondPEAK SPRING
Low 8:48PM −0.34m
May 21 🔑
LESSEE OUTDRAIN START!
Low 9:49PM −0.27m
May 22
Drain Day 2Spring
Low 10:44PM −0.17m
May 23
Drain Day 3Spring ends
Low 11:29PM −0.06m
May 24
Bottom workNeap begins
Low ~12AM +0.05m
May 25
Lime applyNEAP
May 26
TillingNEAP
May 27
Dike repairNEAP
May 28
CleanupNeap min
May 29
Bottom dry
Recovering
May 30
Monitor dikes
May 31
Prep continues
Jun 1
Refill startsSpring building
Low Jun2 −0.08m
Jun 2
Tidal refillSpring
Jun 3
Refill / check pH
Jun 4 ⭐
Final drain?SPRING AM
Low ~7AM −0.24m
Jun 5
SpringWater mgmt
Low ~7:30AM −0.29m
Jun 6 ⭐
Peak SpringSalinity check
Low ~8AM −0.31m
Jun 7
SpringRefill
Jun 8
Spring ends
Jun 9
Fertilizer P1
16-20-0 · 50kg/ha
Jun 10
Lablab watch
Jun 11
Lablab growing
Jun 12
Fertilizer P2
Urea if sunny
Jun 13
Lablab check
Jun 14
Monitor salinity
Jun 15
Habagat watch
Jun 16
Lablab growth
Jun 17
Monitor
Jun 18
Monitor
Jun 19
Neap approaches
Jun 20
Jun 21
Neap
Jun 22
Lablab assess
Jun 23
Neap
Jun 24
Jun 25
LABLAB DECISION
Jun 26
Order fingerlings
Jun 27
Pre-stock prep
Jun 28
Bioassay
Jun 29
Pre-stock check
Jun 30
Stocking prep

Target stocking: July 9, 2026 (BFS-012 schedule)