The published answer, and where it comes from

Almost nothing about an essential oil diffuser is published. This one thing is, and it happens to be the answer to your question.

Most of this series has to tell a maker that the figure they want does not exist. This page does not. CSI's Longevity Base page carries a rest instruction in its own process: “Rest the blend 24-48 hours before bottling for maximum stability and longevity.” The same page explains why the step is there: “This resting period is particularly important for heavy fragrance families - it allows full molecular integration and produces more stable, consistent long-term diffusion.” Both sentences are published copy on a live product page, and they are the only statements about elapsed time anywhere in CSI's diffuser range.

Read what that instruction actually governs, because it is more useful than a general rule about judging a blend. It governs bottling: the page tells a maker to wait 24-48 hours before putting the blend into its vessel. The reason it answers your question anyway is that bottling is the last step of the published process, so the published process is not complete until the rest is complete. A blend you grade before then is a blend you have grabbed halfway through making it.

That reframes the problem usefully. You have not discovered an incompatible pair; you have taken a reading at a point the published method does not recognise as a reading point. Those are very different situations to be in, and they lead to different purchases. The first ends with you buying a different oil or a different base. The second ends with you waiting a day and looking again, which is free.

Four of the five base pages carry the other half of the instruction set — what to do if the blend is still not clear once you have waited. Lift says “If clouding occurs, the fragrance oil may not be fully compatible at that load - reduce fragrance percentage and retest.”, Softness says “If clouding occurs, the fragrance oil may not be fully compatible at that load - reduce the fragrance percentage and retest.”, Depth says “If any clouding occurs, reduce fragrance percentage and retest before proceeding to batch production.” and Longevity says “The blend should remain crystal clear. If clouding occurs, reduce fragrance percentage and retest. Heavy oils like oud can cloud at maximum load in some bases.” The Longevity page also publishes what a correct outcome looks like: “No clouding, no separation when used correctly.” So between the rest and the step-down, CSI publishes a complete procedure — wait, grade, and if it is not clear, reduce the percentage and retest.

A procedure is exactly the kind of published guidance that survives the move from a fragrance oil to an essential oil, and it is worth being precise about why. The 10%, 20% and 30% loads are statements about a material, so they do not transfer to a material the pages do not cover. “Wait 24-48 hours, then compare against a reference, then reduce and retest” is a statement about a method, and a method does not care what you put in the vessel. That distinction is the spine of this page.

What you actually mixed, in CSI's convention

Before you can compare your blend with anybody's figure, you have to express it the way the figures are expressed.

CSI's reed and car diffuser base pages state fragrance load as a percentage of the total finished blend. The published figures are 10% as a starting point, 20% as the recommended working load and 30% as the maximum, with 75% base plus 25% fragrance oil given as the typical working blend and a worked example that reads: for a 100 ml finished diffuser at 25% fragrance, use 75 ml of base and 25 ml of fragrance oil. So a 100 g bottle at the recommended rung is 20 g of oil with 80 g of base; at the published start 10 g with 90 g; at the typical working blend 25 g with 75 g; at the maximum 30 g with 70 g.

The candle convention runs the other way, because there the load is a percentage of the wax weight, and most Indian diffuser makers arrive from candles. So the commonest arithmetic slip in this trade is dividing the oil by the base rather than by the total: 20 g of oil into 80 g of base reads as 25% against the base and 20% against the total finished blend. Both are correct arithmetic. Only the second can be set beside 10%, 20% and 30%, and only the second means the same thing to anybody else you describe the formula to.

This matters here for a specific reason: a reading schedule is a comparison across time, and a comparison needs a label that does not move. If your day-two note says “20%” meaning a fifth of the total and your day-twenty-eight note says “20%” meaning a fifth of the base, you have compared two different blends and concluded something about time. Write the grams on the label as well as the percentage, so the percentage can be rechecked from the grams at any point.

Weigh in grams rather than millilitres while you are at it. A diffuser base and an essential oil do not have the same density, so a formula written in millilitres and mixed by weight is not the formula you wrote down — and CSI's published worked example is given in millilitres while every convenience in a small workshop is in grams. Pick grams, record the percentage of the total finished blend beside them, and the schedule stays readable for as long as the vessels last.

Then the honest caveat, which this hundred of posts carries on every page. Those published rungs are written about fragrance oil. No CSI page publishes a load for an essential oil, so when this schedule places vessels at 10%, 20% and 30% it is borrowing the published bracket because it is the only published bracket in the range — not because those figures have been validated for lavender, lemon, peppermint, marjoram or ylang ylang in a diffuser base.

Before the rest and after it are two different observations

This is the whole point of the page, and it is worth labouring, because it is where the money goes.

A blend mixed in the evening and looked at over breakfast has had perhaps twelve hours. The published rest is 24 to 48 hours. So the morning reading is not a late reading of a finished blend, it is an early reading of an unfinished one, and the two carry different information. The first tells you about mixing, air and temperature. The second tells you about the pair.

Several things that look like failure are normal inside that window. Fine air entrained by stirring takes time to rise out of a viscous liquid. A blend mixed warm and left in a cool room passes through a temperature it will not see again. Oil that was poured onto base rather than base onto oil can sit in a layer that integration has not reached. None of those is a verdict on your oil and base, and all of them are readable only by waiting.

The practical consequence is a rule you can hold to without any equipment: do not make a purchasing decision on a reading taken inside the published rest. Not a decision to buy a different base, not a decision to buy a different oil, not a decision to scrap the batch. At the recommended rung a 100 g bottle holds ₹136.88 of essential oil and ₹175.84 of base — ₹312.72 of liquid — so a batch scrapped at twelve hours on a reading that would have cleared by hour thirty is money thrown away for the sake of a day's patience.

It also changes what you write in your notes. “Hazy” is not a reading; “hazy at 14 hours, against a clear control, at the 20% rung, room at the usual temperature” is. The first cannot be compared with anything. The second can be compared with the same vessel at hour thirty, at day seven and at day twenty-eight, which is how a haze that resolves gets told apart from a haze that does not.

And it is worth saying what a reading after the rest does not settle, so the schedule does not get over-read. A clear vessel at hour thirty-six is a clear vessel at hour thirty-six. The published copy on the Longevity Base page describes the correct outcome as “No clouding, no separation when used correctly.” and nothing on any page promises a given pair will hold that outcome for a month — which is exactly why the schedule has two more readings in it and why those readings, not the first one, are the ones a bulk order should wait for.

The reading schedule, and why three points

One reading is an anecdote. Two is a direction. Three is something you can place an order on.

The schedule has three reading points: after the published 24-48 hours rest, at seven days, and at twenty-eight days. Each one answers a question the others cannot. The first asks whether the pair is clear at all once the published process is complete. The second asks whether that answer is holding. The third asks whether it will still be true when a customer opens the box, which is the only question a bulk order actually depends on.

Three rungs rather than one, for the same reason. If all three of 10%, 20% and 30% are clear at every reading, you have a choice to make on cost and strength rather than a problem to solve. If the lower two hold and the top one hazes at day seven, you have found a ceiling between two rungs and a published response to it. If all three haze, the pair wants a quieter formula or a different base, and you have learned that in one sitting instead of three.

Mix everything in one sitting, with one scale, one vessel type, one fill weight and one set of closures. Four pairs mixed across three evenings are four experiments rather than one schedule, and the differences a reading schedule is looking for are smaller than the differences three evenings can introduce. This is also why each pair is mixed as a single 50 g batch and then split: the room vessel and its reference are then the same liquid, not two attempts at the same liquid.

Keep the room vessels where the product will actually live. An Indian room in October is not a cupboard, and the Longevity Base page's own claim about temperature is worth quoting for what it is about: “Does not evaporate too fast in Indian summer heat or fade too soon in humidity. Consistent diffusion performance across the range of temperatures that Indian homes, offices, and cars experience.” That is published copy about that base's intended performance across Indian conditions, for fragrance oils. Your schedule is how you find out what your own pair does in your own room, which no page can tell you.

Then leave them alone between readings. Every time a vessel is opened, warmed in a hand or shaken to look at it, you have changed the thing you are measuring — and on a three-point schedule there is no way to tell that disturbance apart from a real change. Grade by eye through the glass, in the same light, at the same time of day, and record it before you move on to the next vessel.

The retained reference, kept cool and dark

A reading on its own is an impression. A reading against a reference is a measurement.

Each pair is split into a room vessel and a retained reference. The reference is the same liquid, sealed, dated, labelled with its grams and its load as a percentage of the total finished blend, and kept somewhere cool and dark. Its job is not to be the product. Its job is to be the version of the blend that has experienced as little as possible, so that when the room vessel changes you can see whether the change came from the formula or from the room.

That distinction is otherwise unavailable to you. Suppose the 20% room vessel is faintly hazy at day seven. Against nothing, that is a worrying observation and a reason to doubt the pair. Against a reference that is equally hazy, it tells you the change is in the blend and the room is irrelevant. Against a reference that is still clear, it tells you the room did it — light, warmth, a cold night, a cycle between the two — and the formula may be perfectly serviceable in a different room or a different bottle.

Keep the base-only control pair for the same reason, one level down. The control tells you what clear looks like in your glass, in your light, on that day, which is the baseline every other grade is read against. A control costs almost nothing: the pair of control vessels is 50 g of base, ₹109.90 at the 500 ml pack rate, and the Pure Performance page describes its own appearance as “Crystal clear appearance works with any label design and shows off coloured fragrance blends beautifully in glass bottles.” — so a hazy control is telling you about your vessel or your handling rather than about any oil.

Vessel choice matters more than it looks. A 25 g arm is roughly twenty-five millilitres, so the 50 ml gold bottle is the right size — about half full, which leaves a sensible headspace and a readable depth of liquid. The same arm in a 120 ml bottle is a shallow film at the bottom of a tall vessel, which is hard to grade and sits under far more air. One pack of ten 50 ml bottles at ₹826.00 gives you 10 matched vessels for the 8 vessels the schedule needs, leaving 2 for repeats.

Keep reeds out of the sealed vessels. Reeds change the liquid they stand in — they wick, they draw, they can shed — and a vessel with a reed in it is measuring the reed as well as the blend. The behaviour of a bottle on reeds is a real and separate observation, and the sibling page on the five-arm first trial designs that arm; this schedule is about the liquid, and the liquid is read through clean glass. If you do want a reeded arm running alongside, give it its own bottle and five reeds at ₹45.00 and read it on its own sheet.

What gets written down at each reading

The schedule is only as good as the sheet. Four lines per vessel, three times, and you own a result.

At each reading, for each room vessel, write four things: the clarity grade against the reference, the clarity grade against the control, whether there is any separation visible at the surface or the base of the vessel, and the room condition in whatever terms you can repeat — warm day, cool night, direct sun on the shelf in the afternoon. Four lines, eight vessels, three readings: twenty-four entries in total, and the whole thing fits on one page.

Grade clarity in words you will use the same way next month rather than in numbers you will not. Clear, faint, hazy, milky, separated is enough of a scale, and the discipline that makes it work is grading against the reference and the control first, before writing anything. Numbers invite false precision; the pair of comparisons is the measurement, and the word is only the note.

Photograph each reading, all eight vessels in one frame, in the same place and the same light, with the date in the shot. A photograph is not a grade — a camera's white balance will cheerfully erase a faint haze — but a run of three photographs taken the same way is the only thing that will settle an argument with yourself in week four about whether the day-seven vessel really was clearer.

Keep the sheet with the bottles rather than on a phone. The reason is practical: the next person to read these vessels may be you in four weeks with a different question, or somebody else in your workshop, and a schedule whose record lives in one person's camera roll is a schedule that gets abandoned at reading two. Three readings over twenty-eight days is a long time in a small business.

And record what you did not do as well. If a reading was taken a day late, write the real date rather than the planned one. If a vessel was moved, say so. The value of this record is entirely in its honesty: it is the only evidence that will ever exist about how your pair behaves over a month, because CSI publishes no ageing data, no stability data and no shelf life for any base or any essential oil in a diffuser, and no supplier's page can be substituted for it.

Calendar time costs nothing and cannot be bought later

The cheapest input in your whole plan, and the only one that is not for sale.

Price the schedule and the argument makes itself. It consumes 170 g of base and 30 g of oil: ₹373.66 of base at the 500 ml pack rate and ₹205.32 of essential oil, ₹578.98 in total. Against the ₹23,196.00 that fifty finished units represent, that is 2.5% — fifty units are 40.06 times the schedule's cost. Against the ₹15,636.00 of base and oil a fifty-bottle run actually requires, it is 3.7%.

The materials are also recoverable in a way the time is not. One 500 ml base pack at ₹1,099.00 holds 500 g and covers the schedule's base with 330 g left over, which at the recommended rung is 4.12 finished 100 g bottles' worth — 4 whole ones. So the base you buy for the schedule is not consumed by it; most of it goes on to make product. The oil behaves differently, because the schedule consumes all of it: two 15 g packs at ₹205.32 cover the 30 g exactly, with nothing to spare, so a spilled vessel means opening a third pack. Spent on product rather than on readings, that 30 g would have made 150 g of finished blend at the recommended rung.

What you cannot recover is the twenty-eight days. If you place a bulk order today and start the schedule today, you will know at day twenty-eight whether the order was a good idea — and you will have owned the stock for four weeks either way. If you start the schedule today and order at day twenty-eight, you have spent the same twenty-eight days and you know the answer before the money moves. The two plans cost the same in calendar time and differ entirely in what is at risk.

That is the whole case for starting before the order rather than after it, and it is worth putting in stock terms. A fifty-bottle run at the recommended rung needs 8 packs of 500 ml base at ₹8,792.00 and 2 packs of 500 g oil at ₹6,844.00. Those 8 base packs meet the requirement exactly, with nothing to spare, so there is no slack in that order to absorb a formula change either. A ₹578.98 schedule that runs first is not a delay; it is the thing that makes the ₹15,636.00 order a decision rather than a bet.

There is one more reason the timing runs this way round in the essential oil range specifically, and it is a purchasing one. None of the five stocked essential oils has a quantity break above the 50 g pack — lavender holds the same ₹6,844.00 a kilogram at every size its page quotes, and lemon, peppermint, marjoram and ylang ylang stop improving at the 50 g pack — so waiting four weeks before buying the oil in quantity costs you nothing per gram. Delay is free on this shelf in a way it is not on a fragrance oil, where the rate does improve with size. The sibling page on the per-kilogram cost of an essential oil against a fragrance oil works that comparison through properly.

The honest limit of the published figure

The rest is published. It is not published about your oil, and the difference matters.

The 24-48 hours rest appears on a product page written about fragrance oil, exactly like the 10%, 20% and 30% load band, the clarity step-down and the published fragrance family lists. CSI publishes no load, no dose, no compatibility statement, no flash point, no safety data sheet, no IFRA certificate, no allergen list, no ageing figure and no shelf life for any essential oil in a diffuser. So the rest is the best available starting schedule rather than a validated one for your material.

The reason it still transfers reasonably is the one drawn earlier: it is advice about a procedure rather than about a material. A rest period is a statement that integration takes time and that a reading before integration is unfinished — and that is as true of a blend whose oil came from a still as of one whose oil came from a perfumer's bench. What does not transfer is any expectation that 24 to 48 hours is the right amount of time for your pair. It might be short. The schedule's second and third readings exist precisely because it might be short.

If you want the published figures to apply as written, there is a straightforward alternative, and it is worth knowing before you spend four weeks. Run the identical eight vessels with a fragrance oil in a family the pages name, and the rest, the load band, the clarity step and the family map all apply as published. CSI's florals such as Lavender Fragrance Oil at ₹540.00 for 100 g, Jasmine and British Rose, or a resinous oil such as Woody Oud, sit in the families the base pages name. That is not an argument for preferring one material over the other, and it carries no safety implication either way: it is the difference between testing inside a published range and testing a range you have borrowed.

It is also worth noticing what the same-scent comparison does not give you. Lavender Fragrance Oil at ₹5,400.00 a kilogram and lavender essential oil at ₹6,844.00 share a scent name and nothing else that this page can verify. A clear result on one tells you nothing about the other, because compatibility is a property of the pair at a load and the pairs are different. If you run both, run them as separate vessels on the same sheet and resist the temptation to let the easier result stand in for the harder one.

One further limit, stated because it is where this kind of page usually over-reaches: nothing in the schedule, and nothing in the catalogue, supports a claim about what the finished diffuser does for the person in the room. No therapeutic, medicinal or wellness benefit belongs on your label or in your listing — CSI publishes none, this page measures none, and the claim is regulated. Nor is an essential oil safer than a fragrance oil on grounds of origin: each formulation needs its own hazard assessment, whatever limits apply to it, its own stability testing and truthful ingredient labelling. “100% Pure” is the published product title and is a statement about the oil, not about a finished diffuser; Lift is published as a base for uplifting, mood-boosting scents, which describes the fragrance character the base is built to carry rather than an effect on anyone breathing it.

Still moving at four weeks: what that tells you

The most valuable result this schedule can give you is also the one nobody has written down.

Suppose the 20% room vessel was clear after the published rest, clear at seven days, and faintly hazy at twenty-eight. Its retained reference is still clear. That is a genuine finding and it is not described anywhere in CSI's catalogue, because the catalogue publishes no ageing figure, no stability data and no shelf life for any base or any essential oil in a diffuser. You have learned something about your own pair that no page could have told you, and you have learned it for ₹578.98.

What to do with it depends on which vessel moved. If the top rung moved and the lower two held, you have a load-dependent result and the published response is the step-down: four of the five base pages instruct a maker to reduce the fragrance percentage and retest. If every rung moved including the lowest, the published lever has already been pulled and the answer is a different base or a different oil, with the pair tested again from the start. If the reference moved and the room vessel did not, look at your reference storage before you conclude anything about the formula.

Cost the step-down honestly, because it has two legs and the second one surprises people. Dropping a 100 g bottle from the published 20% rung to the published 10% rung takes ₹68.44 off the oil and adds ₹21.98 of base, because the bottle still has to be full — so the liquid falls from ₹312.72 to ₹266.26, a net ₹46.46. And a 500 ml base pack then fills fewer bottles, 5.56 instead of 6.25, because each bottle wants more base. The step-down is a real saving, smaller than the oil line suggests, with a larger base order attached.

Whatever the result, do not reach for a conclusion the schedule cannot support. A blend that hazes at day twenty-eight in your room has not been shown to haze in a customer's room, and a blend that holds for twenty-eight days has not been shown to hold for six months. Three readings over four weeks is a month's evidence. It is far better than a morning's evidence, which is what you had when you started reading this page, and it is the most any maker in this range can honestly claim, because there is no published figure to appeal to above it.

Which is why the retains stay on the shelf after the decision. Keep the reference for whichever rung you decide to produce at, dated and labelled, and look at it again at three months and at six. Those two extra readings cost nothing — the vessel is already mixed and already stored — and they are the only way you will ever find out what your own formula does over a season. The live CSI page on testing performance over thirty days covers the in-service measurements that run alongside this, for fragrance oils; the clarity schedule here is the liquid half of the same discipline.

What to buy to run the schedule once

One base pack, two small oil packs, ten matched bottles. That is the entire instrument.

The base first. The schedule needs 170 g, and one 500 ml pack at ₹1,099.00 holds 500 g — it covers the schedule with 330 g left, 4 whole 100 g bottles' worth at the recommended rung. A single 100 g trial pack does not cover it: it falls 70 g short. Two trial packs at ₹650.00 hold 200 g and cover it with 30 g left, which is not a whole bottle, so when the schedule ends you own a result and no material.

The rates run the other way, which is worth knowing rather than worrying about. The 500 ml pack is ₹2,198.00 a kilogram, or ₹219.80 per 100 ml; the 100 g trial pack at ₹325.00 is ₹3,250.00 a kilogram, 47.86% dearer per gram. On the 170 g this schedule consumes that is ₹373.66 against ₹552.50, a difference of ₹178.84. The trial pack is dearer per gram precisely because it is a testing size, and it is the right purchase only if you have no intention of making product afterwards.

The oil next. The schedule needs 30 g, and two 15 g packs of lavender essential oil hold 30 g — they cover it exactly, with nothing to spare, so a spilled vessel or a tare error means opening a third pack. One 50 g pack at ₹342.20 covers it with 20 g over instead, for ₹136.88 more. Because the rate is the same ₹6,844.00 a kilogram at every pack size that page quotes, neither choice costs you anything per gram; the choice is only about whether you want oil left over.

Then the glass, which is the instrument rather than the packaging. One pack of ten 50 ml gold reed diffuser bottles at ₹826.00 is ₹82.60 a bottle and gives you 10 matched vessels for the 8 vessels the schedule needs, leaving 2 spare for a repeat. Matched is the operative word: eight vessels of the same shape and glass thickness, read in the same light, is what makes a faint haze comparable between rungs.

Which base to run it in is a separate decision, and the published family map is the honest way to make it. CSI classifies lavender and ylang ylang as florals, peppermint and marjoram as green and lemon as a fresh citrus — editorial classifications, not published facts about those oils — and the Lift page names floral, citrus and green among the families that base is built for. Pure Performance is the neutral alternative, positioned on its own page for testing, with the specification line “Fixatives: None - clean base, no additives.”; Depth and Softness are also ₹1,099.00 for 500 ml, and Longevity is ₹1,296.00, which is ₹39.40 more per 100 ml at ₹259.20.

Add it up and the list is ₹2,130.32: one 500 ml base pack, two 15 g oil packs and a pack of ten 50 ml bottles, or ₹2,240.32 with Standard freight on the base. Freight is quoted on the base only, from its stored packed weight of 1 kg — ₹110.00 Standard, against ₹80.00 for the lighter 0.2 kg of two trial packs, a difference of ₹30.00. The whole list is 9.18% of what fifty finished units represent.

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