My 9 cm Candle Has Two Good Flames but the Melt Pool Becomes Very Deep After Three Hours — How Do I Correct It Without Losing Full-Width Melting?
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How do I cut the depth without losing full width? Test moves that remove surplus heat but leave enough to reach the glass by the end of the session: the pair one size down (2 × C2 → 2 × C1), the same pair moved 5 mm further apart, or simply a shorter session. Two candles per arm, same everything else.
Which move usually wins? The one whose pool reaches full width by about 3 hours with a depth of about 1 cm or less. In our worked example that was the C1 pair: full at 3 hours, 8 mm shallower than the control. Your candle may differ, which is why you log it.
What does the test cost? Six 300 g candles at 8% (worked example): 144 g of oil, 1,656 g of CSI 464, eight C2 and four C1, ₹1,745.77 of materials, your own jars not included. The shorter-session check costs nothing.
- Straight answer: how to cut depth and keep the width
- Where a deep pool comes from when the flames look right
- Logging depth and width at the same moments
- Three moves that cut depth, and what each risks
- The six-candle test, and how to read it
- Grams, wicks and rupees
- What to buy, and what to skip
- Frequently asked questions
Where a deep pool comes from when the flames look right
Two flames melt wax outward and downward at the same time. While the pool is still spreading, most of the new melt shows up as width. Once the pool touches the glass all round, there is nowhere left to spread, and the same two flames keep supplying heat. The only direction left is down. So a candle can have calm, well-sized flames, a clean glass and no soot, and still end a three-hour session with a pool well past the commonly cited 0.5–1 cm range. Nothing is wrong with each flame; there is simply more heat than the session needs.
That is why "two good flames" and "very deep pool" are not contradictory. Flame height tells you about each wick's burn. Depth tells you about the total heat put into the pool over time. A pair of wicks is two heat sources in one pool, and in a jar measured 9 cm outside (8.3 cm inside on an assumed 0.35 cm wall), each wick serves about 27.05 cm² of a 54.11 cm² pool. Whether that is too much depends on your wax, oil, fill and room, which is why the fix comes from a log, not a chart.
Depth also has a place where it concentrates. Between two wicks, both pools overlap, and the midpoint commonly ends up the deepest part of the candle. Near the glass the pool is shallower. When makers say "the pool is very deep", they are usually measuring the middle.
This page is about the first sessions, near the top of the jar. A pool that is fine at the top and only goes deep in the lower half is a different reading, charted by remaining height in the deep-pool-near-the-bottom post. And if a single-wick candle is 1 cm deep at four hours, the depth curve and combined heat rule for one wick are the 7.5 cm single-wick depth curve.
Logging depth and width at the same moments
Most makers measure depth once, when they blow the candle out. That tells you the pool is deep but not when it went deep, and the "when" is the whole diagnosis. Take two readings at each check, at 1, 2 and 3 hours, in burns 2 and 3 (burn 1 starts from a cold candle and is less representative).
| Check | Width | Depth | Also note | What it tells you |
|---|---|---|---|---|
| 1 h | Pool width on the short axis (at right angles to the wick line), mm | Depth at the midpoint between the wicks, mm | Flame heights, trimmed | Width still growing: normal |
| 2 h | Width on the short axis; note the time it first reads full | Depth at the midpoint and about 1 cm from the glass | Flames, soot, carbon | The full-width time lands here or at 3 h |
| 3 h | Width (should read full) | Depth at the midpoint and near the glass | Flames, soot, carbon; flame lean | Depth past about 1 cm = surplus heat |
Why the short axis? With two wicks on a line through the centre, the pool usually reaches the glass along that line first, because each wick sits 2.15 cm from the glass there (at 4.0 cm apart in an 8.3 cm inside). The walls at right angles to the line are 4.61 cm from each wick, so the pool meets them last. "Full width" means full on that short axis. How ring shape maps onto wick geometry in a wider jar is the 10 cm ring-shape map.
How to take depth. Use a marked skewer, dipped straight down and read at the wax line, exactly as described in the single-wick depth post linked above. Dip at the midpoint between the wicks and again about 1 cm from the glass, and keep hands and skewer clear of the flames. Width is a ruler held just above the rim, read from directly above. Photograph both.
What to calculate. Two numbers per candle: the first check at which the width read full, and the depth added between that check and the end of the session. In the worked example the control pair was full width at 2 hours, 10 mm deep, and added 6 mm more in the third hour. That 6 mm is the surplus. The goal is not to eliminate it (depth always grows a little) but to bring the 3-hour depth back to about 1 cm without pushing the full-width time past the end of the session.
The rule-of-thumb session for this width is about 3.3 hours (roughly one hour per 2.5 cm of diameter, very rough), so a 3-hour check is a fair end point for the test. Log the same three checks for every arm below, in the same room, on the same days.
Three moves that cut depth, and what each risks
| Move | How it cuts depth | What it can cost you | Test |
|---|---|---|---|
| 2 × C2 → 2 × C1, same spacing | Less fuel in each flame: less heat everywhere | Width may reach the glass later, and the short-axis walls are the first to lag | 2 candles, one C1 20-pack |
| Spacing out, 5 mm (4.0 → 4.5 cm) | Less overlap between the two pools at the midpoint, where the depth is greatest | Wicks sit 1.90 cm from the glass along the line (was 2.15); short-axis walls get 1.1 mm farther | 2 candles, no new wicks |
| Shorter sessions (read the control at 2 h) | No change to the candle; the depth never reaches its 3 h figure | Customers burn longer than labels say; the fix lives on the label, not in the jar | No candles, nothing to buy |
Size down: 2 × C2 → 2 × C1
The most direct way to cut total heat. Each flame draws less fuel, so both the width curve and the depth curve flatten. The risk is the width: the short-axis walls, already the farthest points from both wicks, are the first to be left behind. In the worked example the C1 pair was at 89% of full width at 2 hours and only reached the glass at 3 hours, which is why its depth stayed at 8 mm. That is a pass, but only just: a C1 pair that needs the full 3 hours in a warm room may need longer on a cool one. It costs ₹7.08 less in wicks per candle, which is not a reason to choose it.
Space out: the same pair, 5 mm further apart
Moving the wicks from 4.0 to 4.5 cm apart doesn't reduce total heat. It moves the two heat sources further from each other, so their pools overlap less at the midpoint, where the depth is greatest. The ends of the wick line get closer: each wick moves from 2.15 to 1.90 cm from the glass along the line. Geometry says the short-axis walls get slightly farther (4.61 → 4.72 cm, 1.1 mm more), so outward moves don't help a ring on the short axis. In the worked example this arm cut the 3-hour depth by 4 mm and kept full width at 2 hours, but still ended over 1 cm. Small steps matter: a 5 mm move is enough to show a direction; a 10 mm move can start the flames leaning toward the glass, which is the wall-gap trade.
Shorten the session: the free arm
Your control already tells you what a shorter session does: read its 2-hour depth. In the worked example the control was full width at 2 hours with 10 mm of depth, inside the range. A label that says "burn for up to 2 hours" would, on paper, solve the problem without pouring a candle. Argued against our own interest: it also costs you nothing, and we'd rather you know that before buying wicks. The catch: customers burn for as long as they are in the room, and many ignore labels. A candle that is only right if the customer stops at 2 hours is fragile; treat this arm as a fallback, or as a second line of defence behind a wick change, not as the fix. Burn-length labels for multi-wick candles are part of the multi-wick life-cycle spec.
The six-candle test, and how to read it
| Arm | Width | Depth | First full width | Surplus after full width |
|---|---|---|---|---|
| Control · 2 × C2 at 4.0 cm | 66 mm (1 h) · 83 mm (2 h) · 83 mm (3 h) | 5 · 10 · 16 mm | full at 2 h | 6 mm added in hour 3 |
| Arm B · 2 × C2 at 4.5 cm | 64 · 83 · 83 mm | 4 · 8 · 12 mm | full at 2 h | 4 mm added in hour 3 |
| Arm C · 2 × C1 at 4.0 cm | 52 · 74 · 83 mm | 3 · 6 · 8 mm | full at 3 h | 2 mm added in hour 3 |
Read it as the diagram does. The control and arm B both reach the glass at 2 hours; B then digs less, because its two pools overlap less, but still passes 1 cm. The control was already at 80% of full width after 1 hour. Arm C reaches the glass only at the last check (it was at 89% of full width at 2 hours), so it has little time left to dig. In this worked example arm C is the candidate. In yours, any of the rows below can happen.
| What the log shows | What it means | Next step |
|---|---|---|
| Arm C reaches full width by 3 h in burns 2 and 3, depth about 1 cm or less | C1 pair is the candidate; the size was the surplus | Full life on 2 × C1 to about 1 cm left |
| Arm B cuts depth to about 1 cm or less and holds full width | The overlap at the midpoint was the surplus; spacing is the fix | Full life on 2 × C2 at 4.5 cm; nothing to buy |
| Both pass | Take the arm with more depth margin at 3 h, because depth commonly grows lower in the jar | Full life on that arm; keep the other as the fallback |
| Arm C in range on depth but the short-axis walls still carry a ring at 3 h | C1 is a little short, C2 a little long, and CSI lists no sized wick between them | Round 2: 2 × C1 at 3.5 cm (2 candles), or the in-between options |
| Neither arm reaches depth of about 1 cm by 3 h | The surplus is bigger than one step, or something else adds heat (room, trim, fill, wax) | Check the room and trim first; then round 2 combines both moves, 2 × C1 at 4.5 cm |
Two notes on the harder rows. If C1 is short on the short axis, moving the C1 pair inward to 3.5 cm brings each wick 1.0 mm closer to those walls (4.61 → 4.50 cm) while putting more overlap back in the middle: a small lever, worth one round of two candles, not more. If it doesn't close the ring, you are in the gap between two CSI sizes, and the honest options, including another wick series, are in the in-between wick post. If neither arm gets depth in range, the next round combines both moves (2 × C1 at 4.5 cm), two candles, 48 g of oil (₹268.80; the 6 g left from round 1 won't cover it, so add a 50 g bottle at ₹280.00). That is a second change, and you already know from round 1 what each did on its own, which is why it is allowed now and not before.
Close cousins in this cluster: when a pair makes the glass very warm rather than the pool deep, the four levers (both down, one down, spacing in, shorter session) are compared for heat in the 9 cm warm-jar post; when two wicks set too close make one hot central pool, the spacing ladder is the too-close pair; and when a pair melts the whole surface very fast, lighting one wick on its own is the single-lit diagnostic.
Grams, wicks and rupees
Materials consumed by the six candles: 144 g of Bergamot Amber (₹806.40), 1,656 g of CSI 464 (₹840.25), 8 C2 and 4 C1 (₹99.12): ₹1,745.77, jars not included because they are your own. From nothing, the cash is ₹2,067.20: Bergamot Amber 100 g and 50 g (₹840.00, leaving 6 g), two 1 kg bags of CSI 464 (₹1,014.80, leaving 344 g), a C2 10-pack and a C1 20-pack. If you already own the oil, wax and C2, the only purchase is the C1 pack, ₹118.00.
Per candle, oil, wax and wicks only: ₹293.32 on a C2 pair and ₹286.24 on a C1 pair (₹134.40 of oil, ₹140.04 of wax, ₹18.88 or ₹11.80 of wicks). The wick change moves the cost by ₹7.08 a candle; it is the depth, not the money, that decides. All figures exclude labour, freight, packaging and GST.
Jars. CSI lists no jar at 9 cm. Its nearest wide listing is the Apothecary Glass Candle Jar with Dome Lid, which states about 10 cm (outer) and "Safe for hot-pour up to 85°C", at ₹212.40 (500 gm) and ₹250.00 (700 gm). It is a different jar, so a result from yours would not carry over to it. Don't buy it for this test.
What to buy, and what to skip
Five items, chosen on page statements, price and stock on 29 September 2026. CSI publishes no wick-performance data, so nothing here is ranked on burn results. Oil candles are counted at 24 g (300 g fill) and 12 g (150 g).
| Pack | Price | Per unit | What it covers here |
|---|---|---|---|
| Thin (C1) / 10 | ₹59.00 — Out of stock | ₹5.90 | Out of stock on 29 September 2026 |
| Thin (C1) / 20 | ₹118.00 | ₹5.90 | arm C's two pairs, 16 spare for round 2 and full life |
| Thin (C1) / 50 · 100 · 500 · 1000 | ₹295.00 · ₹590.00 · ₹2,950.00 · ₹5,900.00 | ₹5.90 | production, after full life |
| Thick (C2) / 10 | ₹94.40 | ₹9.44 | the control and arm B, 8 wicks, 2 spare |
| Thick (C2) / 20 · 50 · 100 · 500 · 1000 | ₹188.80 · ₹472.00 · ₹944.00 · ₹4,720.00 · ₹9,440.00 | ₹9.44 | only if you pour more C2 controls |
| Pack | Price | Per unit | What it covers here |
|---|---|---|---|
| Single tool | ₹399.00 | ₹399.00 | one jar at a time while the wax sets |
| Size | Price | Per gram | 300 g candles at 8% (24 g) | 150 g candles at 8% |
|---|---|---|---|---|
| 15 g | ₹105.02 | ₹7.00 | none (under 24 g) | 1 |
| 50 g | ₹280.00 | ₹5.60 | 2 | 4 |
| 100 g | ₹560.00 | ₹5.60 | 4 | 8 |
| 500 g | ₹2,718.00 | ₹5.44 | 20 | 41 |
| 1 kg | ₹5,437.00 | ₹5.44 | 41 | 83 |
| Pack | Price | Per unit | What it covers here |
|---|---|---|---|
| 500 g | ₹260.00 | ₹0.52 per g | not enough for one arm and a half |
| 1 kg | ₹507.40 | ₹0.51 per g | two bags cover all six (1,656 g), 344 g left |
| 5 kg | ₹2,537.00 | ₹0.51 per g | the same per gram; for the full-life candles too |
| 10 kg | ₹5,074.00 | ₹0.51 per g | production; flat per gram from 1 kg |
| Pack | Price | Per unit | What it covers here |
|---|---|---|---|
| Single | ₹177.00 | ₹177.00 | same trim on all twelve wicks before every session |
Skip: Cotton Braided as a "fix" for depth; it is CSI's largest ready-made cotton wick, and a single is a different build with its own test. Skip a bigger pack of anything until an arm passes its full life: every wick is flat per wick at every pack size. And skip a new oil: this is a heat question, not a scent one.
CandleMakingSuppliesIndia sells the wicks, oil, wax and tools named here, and does not sell finished candles. This page still says that one arm of the test costs nothing, that a 5 mm move may be the whole fix, and that our range has no sized, tabbed wick between C1 and C2.
Every price was verified on CSI's live store on 29 September 2026. Stock was checked per size: the Eco C1 10-pack is out of stock on that date and is flagged wherever it appears; every other size shown is in stock. Load, cure and wick wording is quoted from the product pages; where a page is silent in the text we captured, we say so.
The paired log, the three moves, the pass rule and the worked-example readings are our judgement or illustrations; the 0.35 cm wall, 300 g fill and spacings are worked-example inputs; depth (about 0.5–1 cm), trim and session figures are commonly cited rules of thumb. CSI publishes no wick-performance data. For bulk pricing, GST invoicing, and MSDS and IFRA documentation on request, message us on WhatsApp at +91 7397976926.
Frequently asked questions
- I’m Using an 8.5 cm Jar with Soy Wax and One Cotton Wick — The Centre Melts Well but a Thick Wax Ring Remains; Should I Wick Up or Consider Double Wicking?
- My 9 cm Double-Wick Candle Has Excellent Hot Throw but the Jar Becomes Extremely Warm — Should I Reduce Both Wick Sizes?
- I’m Double-Wicking a 9 cm Jar — How Far Apart Should the Two Wicks Be Positioned Before I Begin Comparing Wick Sizes?
- My Two Wicks Are Too Close Together and Create One Extremely Hot Central Melt Pool — Can Spacing Alone Fix the Problem?
- My Double Wicks Are Too Close to the Glass and the Sides Become Very Hot — How Should Wick Placement Balance Edge Melting and Container Temperature?
- My 8.5 cm Double-Wick Candle Melts the Surface Extremely Quickly — Does That Mean the Two Wicks Are Collectively Oversized?
- My 9 cm Candle Passes the First Three Burns but Becomes Too Hot Halfway Down — How Do I Adjust the Wick Without Causing Early-Stage Tunnelling?
- My 7.5 cm Soy Candle Has a 1 cm Deep Melt Pool After Four Hours — How Do I Determine Whether the Wick Is Generating Too Much Heat?
Customer reviews: The six reviews at the top of this page are genuine, published Judge.me reviews left by CSI customers on the product pages named on each card — Eco Candle Wicks, Luxury Soy Wax CSI 464 (Flakes Form) For Container Candles, Luxury Soy Wax Chunks for Jar / Container Candles, Premium Coconut Soy Wax, Premium Coconut Soy Wax CSI 468 (Flakes Form) For Container Candles. They are general product reviews, not assessments of the wick advice on this page. Names, star ratings, dates and products are as recorded by Judge.me and wording is unedited. "Verified buyer" appears only on reviews Judge.me recorded as verified — Subhankar Roy, Jaya Sawlani, Arminder Kaur, Manasa GN, Sakshi Jain. The reviews from Ashwini are published but not recorded as verified, and carry no badge. Reviews below five stars are included as published, not filtered out.
Figures verified 29 September 2026, CSI live pricing: Bergamot Amber Fragrance Oil 15 g ₹105.02 (₹7.00/g), 50 g ₹280.00 (₹5.60/g), 100 g ₹560.00 (₹5.60/g), 500 g ₹2,718.00 (₹5.44/g), 1 kg ₹5,437.00 (₹5.44/g); Eco Candle Wicks Thin (C1) 10 ₹59.00 (out of stock), 20 ₹118.00, 50 ₹295.00, 100 ₹590.00, 500 ₹2,950.00, 1,000 ₹5,900.00; Thick (C2) 10 ₹94.40, 20 ₹188.80, 50 ₹472.00, 100 ₹944.00, 500 ₹4,720.00, 1,000 ₹9,440.00; Wick Setting Tool ₹399.00; Candle Wick Cutter | Candle Wick Trimmer ₹177.00; Luxury Soy Wax CSI 464 500 g ₹260.00, 1 kg ₹507.40, 5 kg ₹2,537.00, 10 kg ₹5,074.00; Apothecary Glass Candle Jar with Dome Lid 500 gm ₹212.40, 700 gm ₹250.00; Cotton Braided Wicks Ready Made 10 ₹120.00. Every other size listed is in stock on 29 September 2026. Per unit = price ÷ grams or units, two decimals.
Non-price figures: load is a percentage of total candle weight (300 g at 8% = 24 g oil + 276 g wax; the standard 150 g candle at 8% = 12 g). The 9 cm outside, 0.35 cm wall, 300 g fill and 3.5/4.0/4.5 cm spacings are worked-example inputs; pool area = π r² on the inside radius; wick-to-wall along the line = r − s/2; to the walls at right angles = √(r² + (s/2)²). Ceilings are as the pages state (CSI 464 up to 10%, pour 80–90°C; Bergamot Amber 6–10% for soy): formulation limits, not regulatory ones. Depth (about 0.5–1 cm), trim (about 5–6 mm) and session length (about an hour per 2.5 cm) are commonly cited rules of thumb. The paired log, pass rule and every width and depth reading are editorial judgement and illustrative. Costs exclude labour, freight, packaging and GST. Diwali 8 November 2026 is a calendar fact.