Gear picks
Dosing reagents
Dosing is where the math on this site pays for itself, because the right product is a direct function of how much alkalinity your tank consumes per day — and that number is small. Once you know it, the decision is mostly about labor and cost per gram. The budget reality is that two-part is just chemistry: sodium bicarbonate (or carbonate) for alkalinity, calcium chloride for calcium, magnesium salts for magnesium. Buying pharmaceutical-grade dry chemical in bulk and mixing your own is by far the cheapest way to dose a reef, which is why the BRS-style pharma reagents anchor the budget end — a tub lasts a heavily-stocked tank the better part of a year. The catch is that it's two or three separate additions to keep balanced, plus mixing. That's the gap an all-in-one like Tropic Marin All-For-Reef closes, and it's our value pick: one bottle that supplies alkalinity, calcium, magnesium, and trace elements in the ratio corals actually pull them out of the water, so you dose a single thing and stop chasing ions against each other. It costs more per unit of alkalinity than DIY two-part, but it removes the part of dosing people get wrong. The premium consideration isn't a different chemical so much as the precision of delivery — a controllable dosing pump turning your daily demand into a hands-off schedule. Whatever you pick, size the pack to demand, not to the tank's gallons: a lightly-stocked 120 can burn through less reagent than a packed 40-breeder. That's exactly what the precision sizing on our dosing calculators is for.
Budget pick
Arm & Hammer Baking Soda — 13.5 lb
~$10Plain baking soda is the cheapest alkalinity source there is — bake it at 250 °F for an hour to convert to soda ash, or dose it raw.
- · Pure sodium bicarbonate
- · 13.5 lb bulk box
- · Bake to convert NaHCO₃ → Na₂CO₃
Budget pick
Calcium Chloride, food grade — 7 lb
~$30Food-grade calcium chloride in a bucket — the cheapest way to run the calcium side of a DIY two-part, as long as you check the hydration state before doing the recipe math.
- · 7 lb resealable bucket
- · Food grade CaCl₂
- · Confirm anhydrous vs. dihydrate before dosing
Budget pick
Epsom Salt (magnesium sulfate), bulk
~$25Plain Epsom salt supplies the sulfate portion of a DIY magnesium blend — roughly one part to five parts magnesium chloride keeps the seawater ratio intact.
- · Magnesium sulfate heptahydrate
- · Blend ~1:5 with MgCl₂ flakes
- · Do not dose alone in quantity
Budget pick
Magnesium Chloride hexahydrate flakes — 5 lb
~$25Hexahydrate flakes are the form every DIY magnesium recipe is written around — buy this rather than an unlabelled powder, or your dose math will be off by a third.
- · 5 lb hexahydrate flakes
- · 0.836 g per 100 L raises Mg ~1 ppm
- · Pair with Epsom salt for the sulfate side
Budget pick
Sodium Bicarbonate, 100% pure — 5 lb
~$20Chemically identical to the alk half of any commercial two-part — 3 g per 100 L raises alkalinity about 1 dKH, and a 5 lb pouch lasts most tanks a year.
- · 5 lb resealable pouch
- · ~3 g per 100 L per dKH
- · Bake at 250 °F to convert to soda ash
Budget pick
Two Little Fishies Kalkwasser (calcium hydroxide) — 2 kg
~$30Saturated lime water in your top-off covers calcium and alkalinity at once and props up night-time pH — the cheapest dosing method there is.
- · Pure Ca(OH)₂ powder
- · ~6 g per gal of top-off at saturation
- · Delivers Ca + alk + pH in one
Value pick
BRS Pharma Calcium Chloride (Ca component)
~$25The calcium half of BRS two-part — anhydrous CaCl₂ dosed against Randy's recipe to track alk consumption gram-for-gram.
- · Anhydrous calcium chloride
- · Matched to BRS recipe calculator
- · Pairs with the bicarb component
Value pick
BRS Pharma Magnesium Mix
~$25The chloride+sulfate blend Randy Recipe 3 calls for — keeps Mg topped up so your Ca and alk dosing actually holds.
- · MgCl₂ + MgSO₄ blend
- · Matches Randy Recipe 3 ratio
- · Dose only when Mg tests low
Value pick
BRS Pharma Sodium Bicarbonate (alkalinity component)
~$25Pharmaceutical-grade sodium bicarbonate matched to the BRS two-part recipe — the same chemistry as baking soda without the oven step.
- · Pre-portioned to BRS recipe math
- · Raises alk without pH spike
- · No baking/conversion needed
Value pick
Red Sea Reef Foundation A (Ca/Sr) — 1 kg powder
~$30Calcium and strontium in the ratio Red Sea's Foundation program assumes — dose it against measured Ca, not on a schedule.
- · 1 kg powder, mixes to concentrate
- · Ca + Sr in reef ratio
- · Part A of the A/B/C program
Value pick
Red Sea Reef Foundation B (Alkalinity) — 1 kg powder
~$30Carbonate powder for the Foundation program — 1 g per 100 L moves alkalinity about 0.33 dKH, so a kilo goes a long way on a mid-size tank.
- · 1 kg powder
- · ~0.33 dKH per g per 100 L
- · Part B of the A/B/C program
Value pick
Red Sea Reef Foundation C (Magnesium) — 1 kg powder
~$30Magnesium for the Foundation program — consumption is slow, so this is the tub you replace least often, but low Mg quietly stalls Ca and alk uptake.
- · 1 kg powder
- · Chloride + sulfate blend
- · Part C of the A/B/C program
Premium pick
Tropic Marin All-For-Reef (liquid, 1 L)
~$35One bottle covers calcium, alkalinity, and trace elements in balance — the simplest dosing system that still grows SPS.
- · Single-part balanced supplement
- · 1 mL / 25 L / 1 dKH consumed
- · Includes trace elements
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