Formalin is approved by FDA for control of fungus (technically water mold) on eggs in fish hatcheries. Concentrations of 1000 to 2000 mg/l can be applied to fish eggs for 15 minutes. Eggs that are hatching should not be treated. Hatchery managers are reminded that sanitation is important for the prevention of fungus on fish eggs. Dead eggs should be removed from the system promptly because they serve as a source of infection for adjacent, healthy eggs.
milliliters (fluid ounces)| Seconds to | Concentration | |||
|---|---|---|---|---|
| Fill 1 gal | GPM | 2000 ppm | 1667 ppm | 1429 ppm |
| Container | Flow | 1:500 | 1:600 | 1:700 |
| 4 | 15.0 | 1703(58) | 1420(48) | 1217(41) |
| 5 | 12.0 | 1362(46) | 1136(38) | 973(33) |
| 6 | 10.0 | 1136(38) | 946(32) | 811(27) |
| 7 | 8.57 | 973(33) | 811(27) | 695(24) |
| 8 | 7.50 | 852(29) | 710(24) | 608(21) |
| 9 | 6.67 | 757(26) | 631(21) | 541(18) |
| 10 | 6.00 | 681(23) | 568(19) | 487(16) |
| 11 | 5.45 | 619(21) | 516(18) | 442(15) |
| 12 | 5.00 | 568(19) | 473(16) | 406(14) |
| 13 | 4.61 | 523(18) | 436(15) | 374(13) |
| 14 | 4.29 | 487(16) | 406(14) | 348(12) |
| 15 | 4.00 | 454(15) | 379(13) | 324(11) |
| 16 | 3.75 | 426(14) | 355(12) | 304(10) |
| 17 | 3.53 | 401(14) | 334(11) | 286(10) |
| 18 | 3.33 | 378(13) | 315(11) | 270/(9) |
| 19 | 3.16 | 359(12) | 299(10) | 256/(9) |
| 20 | 3.00 | 341(12) | 284(10) | 243/(8) |
* to calculate formalin treatment in milliliters = (gpm)(ppm)/17.61
gpm = gallons per minute
ppm = desired parts per million of formalin
* 15 minute treatment time - Use an appropriate
dispenser
* DO NOT treat eggs that are
hatching
