FAULT ISOLATION MANUAL · MAJOR IONS — MAGNESIUM

MG-001 · Magnesium decreasingv1.0.1

Magnesium falls across comparable tests. This sheet isolates why, the way an aircraft maintenance manual would: confirm the reading and the trend, clear the confounds, verify supply and delivery, and only then act. Answer each numbered block and the sheet lights the path.

WHAT YOU'LL NEED

Your magnesium test kit (plus a second kit or fresh reagent)
A graduated container and the dosing calculator
A sample of your freshly mixed salt water
Your tank journal

JavaScript is off, so the interactive sheet can't run — the complete printed logic is below. Start at block 1 and follow the YES/NO links. Nothing about your tank is inferred or stored.

Block 1 — Have you confirmed the reading with a second test (a different kit, or fresh reagent)? (Note: Magnesium titration kits are technique-sensitive and their reagents age: a mis-read endpoint shifts every reading the same direction.)
YES → block 3 · NO → block 2

Block 2 — Retest before troubleshooting: a single reading is not a declining trend. Confirm with a second kit or fresh reagent, then return to this procedure. (Verify — 2 days, MAGNESIUM: A second kit or fresh reagent reproduces the reading within the kits' stated resolution)
END — ESCALATE RETEST

Block 3 — Across at least 3 comparable tests (same kit, same time of day), has magnesium continued to fall from test to test? (Note: Comparable means same kit, same time of day. Magnesium moves slowly, so tests spaced days apart read the trend more reliably than daily tests; and a single low reading is not a declining trend.)
YES → block 9 · NO → block 4

Block 4 — Is magnesium still inside your tank-type target range: 1230–1360 ppm (mixed reef) or 1260–1340 ppm (SPS-dominant)?
YES → block 5 · NO → block 6

Block 5 — MG-001 NOT ACTIVE — magnesium is not on a confirmed declining trend and sits inside your tank-type target range. That establishes only that this fault's entry condition is not met. Log the readings in your journal: a recorded baseline makes the next investigation faster.
END — NO FAULT

Block 6 — Is magnesium BELOW the range (rather than above it)?
YES → block 7 · NO → block 8

Block 7 — BELOW TARGET RANGE, TREND NOT CONFIRMED: restore the level with correction mode, planning the raise at no faster than 50 ppm per day. Keep testing on the same comparable schedule; if a declining trend emerges, run this procedure again. (Note: Raising no faster than 50 ppm per day is BioForge correction policy.) (Verify — 3 days, MAGNESIUM: Magnesium rising on the correction schedule at no more than 50 ppm per day, or back inside your tank-type target range, across comparable tests)
verified resolved → done · problem continues → block 3

Block 8 — ABOVE TARGET RANGE: do NOT dose upward; correction mode only raises magnesium and has no place here. Let routine water changes and consumption bring the level down into range and test on your regular schedule while it settles. (Note: Falling from an elevated level toward range is the system self-correcting. Chasing the number upward re-creates the elevation.) (Verify — 3 days, MAGNESIUM: Magnesium moving down toward or inside your tank-type target range with no magnesium dosing in the interval)
verified resolved → done · problem continues → block 3

Block 9 — During that SAME trend window: any water change, salinity adjustment, calcium or alkalinity correction, or change to any dosing program? (Note: Replacement water with different magnesium, a salinity shift, or a parallel correction can mask or mimic a decline: the window has to be clean before the trend is attributed.)
YES → block 10 · NO → block 11

Block 10 — TREND WINDOW CONFOUNDED — the decline cannot be attributed while the window contains an intervention. Re-establish the trend: 3 comparable tests, same kit, same time of day, with no water changes or parallel corrections. If the decline reproduces, return to this procedure. (Verify — 3 days, MAGNESIUM: Three comparable tests in an intervention-free window still show magnesium falling from test to test)
END — ESCALATE RETEST

Block 11 — Is magnesium currently ABOVE your tank-type target range: 1230–1360 ppm (mixed reef) or 1260–1340 ppm (SPS-dominant)? (Note: A decline at an elevated level is dispositioned differently: no dose-raising action is safe above range.)
YES → block 12 · NO → block 13

Block 12 — ABOVE TARGET RANGE AND FALLING: a decline from elevated toward range is the system self-correcting, and no upward correction is safe from here. Identify what produced the elevation (a correction overshoot, a high-magnesium salt mix), log it in your journal, and monitor while the level settles toward range. (Note: The tank is not required to reach range in three days: if verification fails, the level is reclassified fresh at the range check before any further step.) (Verify — 3 days, MAGNESIUM: Magnesium moving toward or holding inside the target range with no upward dosing in the interval)
verified resolved → done · problem continues → block 11

Block 13 — Does the tank have ANY active magnesium supply beyond water changes: liquid dosing pump, or regular manual dosing on a schedule? (Note: Many tanks replenish magnesium through water changes alone. That is not a fault by itself; but when measured consumption outruns what the water changes return, the decline continues until a supply is established.)
YES → block 17 · NO → block 14

Block 14 — Is magnesium currently BELOW the target range? (Note: Below range adds a second task, restoring the deficit, on top of establishing supply.)
YES → block 16 · NO → block 15

Block 15 — NO MAGNESIUM SUPPLY: consumption is outrunning what your water changes return. Set a maintenance dose sized to measured demand: enter tank volume and the measured drop between comparable tests in the dosing calculator. Also test your freshly mixed salt water for magnesium once: replacement water that mixes low replaces less than the tank loses. (Verify — 7 days, MAGNESIUM: Comparable tests across the week show magnesium holding inside the target range on the maintenance dose)
verified resolved → done · problem continues → block 11

Block 16 — NO SUPPLY AND BELOW RANGE: two separate tasks. First restore the deficit with correction mode, planning the raise at no faster than 50 ppm per day. Then set a maintenance dose sized to measured demand (tank volume + measured drop between comparable tests) in the dosing calculator. Also test your freshly mixed salt water for magnesium once: replacement water that mixes low replaces less than the tank loses. (Note: Correction mode restores a level; the maintenance dose matches ongoing demand. Neither substitutes for the other. Raising no faster than 50 ppm per day is BioForge correction policy.) (Verify — 7 days, MAGNESIUM: Magnesium rising at no more than 50 ppm per day toward range, or back inside the target range and holding, across comparable tests)
verified resolved → done · problem continues → block 11

Block 17 — Is that supply a liquid dosing pump (peristaltic or DC doser)? (Note: The delivery check below, timed container runs, quantifies a liquid dosing pump only. It cannot verify manual dosing consistency.)
YES → block 19 · NO → block 18

Block 18 — UNSUPPORTED SUPPLY METHOD — this revision of MG-001 can verify delivered magnesium for liquid dosing pumps only. With manual dosing, a delivery shortfall (missed doses, inconsistent measuring) cannot be excluded or confirmed here, so this procedure stops rather than guess. Log your supply method and the confirmed decline in your journal; a future revision will add checks for manual dosing. (Note: If several parameters are drifting at once, not just magnesium, a full ICP analysis may be warranted on its own merits. That is a separate decision, not this procedure's exit.) (Why this procedure stopped: MG-001 has no verification procedure for manual dosing: the timed-container check quantifies liquid dosing pumps only. This is a Manual coverage gap, not evidence of a tank fault requiring multi-parameter analysis.)
END — UNSUPPORTED METHOD

Block 19 — Verify actual delivered dose. Run your magnesium doser into a graduated container for a timed 60-second run, twice. Convert the measured mL/day into ppm magnesium delivered with the calculator, then return here.
then → block 20

Block 20 — Across BOTH timed runs, does measured pump output match the programmed dose within ±10%? (Note: ±10% is BioForge equipment-check policy. A single run must not isolate a delivery fault: peristaltic tubing fatigues gradually and output varies run to run.)
YES → block 22 · NO → block 21

Block 21 — DOSING DELIVERY SHORTFALL: the tank received less than the programmed dose, so the decline may be nothing more than under-replacement. Recalibrate the doser or replace fatigued tubing, then reprogram to the verified output and re-run the timed-container check. (Note: Peristaltic tubing loses accuracy long before it visibly fails. Recalibrate on a schedule, not on symptoms. Verification here is the doser's measured output: the magnesium trend is re-checked downstream once delivery is proven.) (Verify — 1 day, DOSER OUTPUT: Two fresh timed 60-second container runs each match the programmed dose within ±10%)
verified resolved → done · problem continues → block 11

Block 22 — Is the tank visibly calcifying (coralline algae spreading or stony corals growing), with calcium and alkalinity consumption recorded on the same journal record? (Note: Coralline algae deposit magnesium-rich calcite and stony corals incorporate magnesium as they grow, so a calcifying tank consumes magnesium alongside calcium and alkalinity, slowly, but continuously. Treat visible growth plus recorded calcium and alkalinity demand as corroboration of genuine consumption, never proof.)
YES → block 23 · NO → block 26

Block 23 — Is magnesium currently BELOW the target range? (Note: Below range means two tasks: restore the deficit AND match demand. In range means one: match demand.)
YES → block 25 · NO → block 24

Block 24 — PATTERN CONSISTENT WITH CONSUMPTION exceeding your magnesium dose: the tank is calcifying and the level is falling despite verified delivery. Raise the magnesium MAINTENANCE dose to match measured demand: tank volume and the measured drop between comparable tests in the dosing calculator. Correction mode is not the tool here: the level is in range; there is nothing to restore. (Note: This corroborates consumption after test error, confounds, missing supply, and delivery shortfall were eliminated. It does not isolate by growth appearance alone.) (Verify — 7 days, MAGNESIUM: Comparable tests across the week show magnesium holding inside the target range on the new maintenance dose)
verified resolved → done · problem continues → block 26

Block 25 — CONSUMPTION EXCEEDS DOSE AND THE LEVEL IS BELOW RANGE: two separate tasks. First restore the deficit with correction mode, planning the raise at no faster than 50 ppm per day. Then set the magnesium maintenance dose to match measured demand (tank volume + measured drop between comparable tests) in the dosing calculator. (Note: Correction mode restores a level; the maintenance dose matches ongoing demand. Doing only one leaves the fault active. Raising no faster than 50 ppm per day is BioForge correction policy.) (Verify — 7 days, MAGNESIUM: Magnesium rising at no more than 50 ppm per day toward range, or back inside the target range and holding, across comparable tests)
verified resolved → done · problem continues → block 26

Block 26 — In the last two weeks: new filtration media, new rock added, or anything curing in the system?
YES → block 27 · NO → block 28

Block 27 — RECENT SYSTEM CHANGE UNRESOLVED — a change in the last two weeks coincides with the decline, but this procedure cannot attribute the decline to it or quantify it from magnesium readings. A full 38-parameter ICP analysis with photo and history context is the next step; note the recent change when you submit. (Why this procedure stopped: A recent system change is an unresolved confounder: this procedure cannot attribute or quantify its effect from magnesium readings alone, and a confirmed decline should not be waited out on an assumption.)
END — ESCALATE DECODE

Block 28 — This procedure cannot isolate the fault from magnesium readings alone: delivery is verified and the tank shows no calcification demand that would account for the decline. A full 38-parameter ICP analysis with photo and history context is the next step. (Why this procedure stopped: Confound window, supply, delivery, and consumption-corroboration checks completed without isolating a cause: a confirmed magnesium decline with verified delivery and no calcification demand to attribute it to needs multi-parameter analysis, not another guess.)
END — ESCALATE DECODE