Neptune’s Harvest and Bloom
Neptune’s Harvest turns the Gloucester catch into fish and seaweed fertilizer. Bloom’s got a fish and kelp tonic too. Here’s how the two lines sit together.
Last checked 5 November 2026 · Public information only
This Fit Report is a summary of publicly available information about Neptune’s Harvest and its products, taken from their own website, labels and published material as of 5 November 2026. We’ve linked each source so you can check it yourself. Rates are as printed on each company’s own pages; we don’t show prices. It isn’t affiliated with, endorsed by or approved by Neptune’s Harvest, and product names belong to their owners. Products, rates and claims change, so please confirm current details with the manufacturer before making any decision. Spotted something out of date? Email nathan@bloomyellowbottles.com and we’ll correct it.
Off the docks, and into the same watering can.
Neptune’s Harvest is a fish house first: liquid fish, fish and seaweed, seaweed, a veg and a flowering formula, a new liquid humate, and dry crab shell and kelp meal. It’s all marine and garden-scale. Bloom shares the fish, kelp and humic ground, then adds what isn’t on their list: cal-mag, silica, sea minerals, a two-part base and a bottle for each stage.
- Stays as is: Crab & Lobster Shell, Kelp Meal, the lawn and turf formulas and the pest products.
- Both have one: fish and kelp, seaweed, humic, a veg feed and a flower feed.
- Not on their list: cal-mag, silica, sea minerals, a carbohydrate additive and stage additives.
Neptune’s Harvest and Bloom in short
Crab & Lobster Shell, Kelp Meal, lawn and turf formulas and their pest line.
Fish-Seaweed Blend, Hydrolyzed Fish, Seaweed Plant Food, Liquid Humate and the veg and flower formulas.
Cal-Mag, Silica, Sea Minerals, SWTNR, Florigen, and the Ultra, Phat, Ooze and Final stage additives.
Where each bottle sits in the cycle
Neptune’s Harvest’s timing in grey, Bloom’s in yellow, across shared stages of the grow.
| Stage | Root | Veg | Flip | 3–4 | 5+ | Last 2 | Flush |
|---|---|---|---|---|---|---|---|
| Neptune’s Harvest, per their pages | |||||||
| Seed soak | |||||||
| Fish-Seaweed Blend | |||||||
| Seaweed Plant Food (alternate feeds) | |||||||
| Tomato & Veg | |||||||
| Rose & Flowering | |||||||
| Liquid Humate (Neptune’s Harvest) | |||||||
| Bloom, per Bloom’s weekly feed charts | |||||||
| Roots | |||||||
| Pre | |||||||
| Ultra | |||||||
| Phat (weeks 3 and 4) | |||||||
| Ooze (wk 5 to flush) | |||||||
| Final (with Ooze) | |||||||
| Seafuel | |||||||
| Seaweed · Humate · Sea Minerals | |||||||
| SWTNR | |||||||
| Cal-Mag | |||||||
| Groigen (foliar, as needed) | |||||||
| Florigen (foliar, as needed) | |||||||
| PK (as needed) | |||||||
| Silica | |||||||
Timing comes from Neptune’s Harvest product pages and their mixing and use page. Liquids go on every 1–2 weeks. Tomato & Veg is for the vegging stage and Rose & Flowering starts once buds appear. Seaweed Plant Food is used in alternate feedings with their fish, so it’s pale. The Liquid Humate page gives rates but no frequency, so it’s pale too. Their pages don’t name a stop week, so bars end before the flush (our read). Bloom’s bars follow its weekly feed charts; pale Bloom bars are as-needed bottles.
Their line, Bloom’s fit at a glance
Matched on job, not NPK. Neptune’s Harvest prints rates per gallon of water every 1–2 weeks; Bloom prints ml per litre on a weekly feed chart. Tap a tag to filter.
Both are fish with kelp. Theirs is North Atlantic catch; Seafuel is tuna and southern bull kelp. Pick one, or test them.
Fish on its own. Seafuel is fish and kelp in one bottle, so it sits between their two.
Both are liquid seaweed. Theirs is North Atlantic Ascophyllum; Seaweed is southern bull kelp.
Both are a liquid humate. Theirs lists 12%; Bloom Humate is 10% humic acid. Run one.
Both feed veg. Theirs is one organic liquid; Bloom runs a two-part base with Pre on top.
Both pick up at flower. Theirs is one liquid; Bloom runs a two-part base with PK as needed.
Dry inputs for the soil mix. Bloom’s liquids go in the water after them.
Turf and lawn are their ground. Bloom doesn’t make a turf product.
Both have a pest line. Read both labels before you run them in the same room.
Calcium and magnesium with iron and zinc, plus trace minerals from sea water, for soil, coco or hydro.
Potassium silicate, labelled 0-0-4, veg through early flower.
They move from a veg formula to a flowering formula. Bloom adds a bottle for the flip, mid flower, late flower and the finish.
Carbohydrates and potassium from veg week 2, and a lights-off foliar for the stretch.
Where the programs complement each other
Their marine liquids, Bloom’s minerals
Cal-Mag, Silica and Sea Minerals aren’t on Neptune’s Harvest’s list. They go in at 0.13–1 ml/L weekly alongside the fish and seaweed a grower already runs.
Stage bottles over a two-formula plan
Their program is a veg formula then a flowering formula. Ultra, Phat, Ooze and Final add timing within flower, and SWTNR and Florigen add a carb and a foliar.
Fish and kelp, side by side
Fish-Seaweed Blend and Seafuel, and their Seaweed Plant Food and Bloom Seaweed, do the same job. A same-room test is the fair way to pick, rather than doubling up (our read).
Why each one fits
What the Bloom product does, the research behind that kind of input, and where it sits in a program that already runs.
Cal-mag, silica and sea minerals
What it does. Cal-Mag is calcium and magnesium with iron and zinc at 1 ml/L weekly. Silica is potassium silicate at 0.33 ml/L weekly, added first. Sea Minerals is trace minerals from sea water at 0.13 ml/L weekly.
How it stacks. Neptune’s Harvest liquids are fish, seaweed and humic. These three are mineral jobs that sit in the same water. Our read: add Silica first, then the rest, and check runoff.
Two formulas, or a bottle per stage
What it does. Ultra at the flip (flower weeks 1–2), Phat in flower weeks 3 and 4, Ooze from week 5 through the final flush, and Final for the last two weeks alongside Ooze. 1–2.5 ml/L, weekly. These are timing tools, so there’s no study cited for them here.
How it stacks. Neptune’s pages split the cycle in two: Tomato & Veg in veg, Rose & Flowering once buds appear. Bloom’s stage bottles can go in on top of either, at the weeks they’re built for (our read).
Fish and kelp, two oceans
What it does. Seafuel is tuna and kelp at 1 ml/L weekly, clone through late flower, tapering at the flush. Seaweed is southern bull kelp at 1 ml/L weekly, seedling through flush.
Reviews of seaweed extracts report effects on growth and stress tolerance across many crops. Work on protein hydrolysates, which fish inputs belong to, links them to nutrient uptake, though stress data is thinner. None of it tests these products or cannabis.
Ali et al. (2021), Plants (review) · Malécange et al. (2023), Int J Mol Sci (review)
How it stacks. This is the shared ground. A grower already on Fish-Seaweed Blend would test Seafuel against it rather than run both at full rate (our read).
SWTNR and Florigen
What it does. SWTNR is carbohydrates and potassium at 1 ml/L weekly, veg week 2 to the flush. Florigen is a 20 ml/L lights-off spray for the stretch to early bloom, every few days as needed, stopping once buds set.
How it stacks. Their Rose & Flowering lists a sweetener among its ingredients. SWTNR is a dedicated carb bottle, so check both labels if you run them together (our read).
Put it side by side
Where both ranges have a product for the same job, the fair answer is a test in your own room. Here’s what to watch and how to keep it fair.
Keeping it fair
- Same plants. Clones off the same mother, same cultivar, same age.
- Same room. Same light, climate, media, pot size and watering.
- Same base. Keep the base feed and EC the same on both sides.
- One change. Change only the product being tested, and write down what you see each week.
Already covered
- Fish. Hydrolyzed Fish Fertilizer and Fish-Seaweed Blend.
- Seaweed and humic. Seaweed Plant Food and the new Liquid Humate.
- Veg and flower liquids. Tomato & Veg, then Rose & Flowering.
- Dry, turf and pest. Crab & Lobster Shell, Kelp Meal, lawn and turf formulas, and repellents.
Stays exactly as is
- Crab & Lobster Shell and Kelp Meal. Bloom has no dry products.
- Lawn and turf formulas. Bloom doesn’t make a turf product.
- Their fish and seaweed. If they’re working in your room, keep them, or test Bloom’s next to them.
Background, science and sources
Who Neptune’s Harvest are
Neptune’s Harvest is a division of Ocean Crest Seafoods Inc., a Gloucester, Massachusetts seafood wholesaler established in 1965. The fertilizer side started in 1986 to turn filleting by-products, which they call gurry, into liquid fish fertilizer, and it’s made on the Gloucester docks.
The range is hydrolyzed fish, fish and seaweed, seaweed, tomato and veg, rose and flowering, lawn and turf liquids, a new liquid humate, crab and lobster shell, kelp meal, and a line of pest repellents. They sell online, through retail stores, through a farm distributor map for commercial growers, and to wholesalers with display racks.
What each company brings
Neptune’s Harvest: Fish, fish and seaweed, and seaweed liquids from the Gloucester catch, veg and flowering formulas, a liquid humate, crab shell and kelp meal, turf liquids and pest repellents, with simple per-gallon rates for gardens, farms and lawns.
Bloom: one additive for each stage of the crop, seaweed, humic and sea mineral inputs, foliar sprays, and weekly feed charts for soil, coco and hydro. Rates and timing are on every product page.
Cropping Solutions, the other brand under Agricultural Organics, isn’t part of this report.
Dose basis: how each side counts
Neptune’s Harvest prints 1 oz per gallon (1:128) every 1–2 weeks for outdoor plants, and 1 tbsp per gallon every 1–2 weeks for houseplants. Bloom prints ml per litre on a weekly feed chart. At 3.785 L to the gallon, 1 oz per gallon is about 7.8 ml/L and 1 tbsp per gallon is about 3.9 ml/L. Their Liquid Humate’s 1 tbsp per gallon for soil is about 3.9 ml/L; Bloom Humate is 2.5 ml/L weekly.
Their liquids go every 1–2 weeks and Bloom’s weekly, and the analyses differ, so the same number on each side isn’t the same amount.
Mix calculator
Rates as printed on each company’s page (1 US gallon is 3.785 L). Bloom’s rates are per litre of nutrient solution, dosed weekly per its feed charts. Pick a product and your tank size.
Humic substances and rootsWell supported
Canellas and colleagues (2015) review humic and fulvic acids as biostimulants in horticulture, linking humic substances to lateral root growth and to changes in roots and shoots tied to nutrient uptake.
Why it matters here: Neptune’s Harvest now sells a Liquid Humate and their veg and flowering formulas list humic acids, and Bloom Humate is a 10% humic acid liquid. The review is general and doesn’t test either product.
Sources, all viewed 5 November 2026
Neptune’s Harvest: Home · About · Products · Mixing and use · Fish-Seaweed Blend · Hydrolyzed Fish · Seaweed Plant Food (Neptune’s Harvest) · Liquid Humate (Neptune’s Harvest) · Tomato & Veg · Rose & Flowering
Bloom: Roots · Pre · Ultra · Phat · Ooze · Final · Seafuel · Seaweed · SWTNR · Humate · Cal-Mag · Groigen · Florigen · Sea Minerals · PK · Euro · Grow · Flower · Silica · OrganiShield
Last checked 5 November 2026. Public information only. Not affiliated with, endorsed by or approved by Neptune’s Harvest; product names belong to their owners. Please confirm current details with the manufacturer. Corrections: nathan@bloomyellowbottles.com. All Fit Reports