EVENT 301 Mixed 09 Yrs/Over 400m Freestyle - Heats
| Heat Number - 1 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 2 | 1 | Matilda MCDONNELL | 11 | Grantham | 8:07.18 |
| 3 | 2 | Thomas KINNEAR | 13 | Grantham | 8:00.20 |
| 4 | 3 | Olivia CHARITY | 12 | Grantham | 8:00.00 |
| Heat Number - 2 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 4 | Florence HARPER | 11 | Grantham | 7:04.00 |
| 2 | 5 | Emilie WEBB | 14 | Grantham | 6:49.25 |
| 3 | 6 | Benjamin GODDARD | 11 | Grantham | 6:48.27 |
| 4 | 7 | Freddie HIRST | 10 | Grantham | 6:38.20 |
| 5 | 8 | Madeline SURTEES | 12 | Grantham | 6:35.00 |
| 6 | 9 | Markas PARAPIJONAVICIU | 11 | Grantham | 6:30.00 |
| Heat Number - 3 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 10 | Hollie-Anne CROOK | 10 | Grantham | 6:30.00 |
| 2 | 11 | Lucy ABBOTT | 12 | Grantham | 6:25.75 |
| 3 | 12 | Leo BARNETT | 12 | Grantham | 6:20.23 |
| 4 | 13 | Elliot GLEAVE | 11 | Grantham | 6:19.82 |
| 5 | 14 | Toby EDMONDSON | 10 | Grantham | 6:18.30 |
| 6 | 15 | Derrin BROCKLEBANK | 10 | Grantham | 6:15.00 |
| Heat Number - 4 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 16 | Isabelle CLAYTON | 12 | Grantham | 6:10.20 |
| 2 | 17 | Eden DYSON | 13 | Grantham | 6:07.79 |
| 3 | 18 | Thomas HILLSON | 11 | Grantham | 6:07.32 |
| 4 | 19 | Arthur BREARLEY-NEWSOM | 13 | Grantham | 6:02.02 |
| 5 | 20 | Jake MCGHEE | 14 | Grantham | 5:57.00 |
| 6 | 21 | George LEONARD | 12 | Grantham | 5:55.80 |
| Heat Number - 5 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 22 | Charlotte GILL | 16 | Grantham | 5:51.95 |
| 2 | 23 | Poppy HATHWAY | 13 | Grantham | 5:51.22 |
| 3 | 24 | Elisabeth KINNEAR | 14 | Grantham | 5:42.10 |
| 4 | 25 | Fabian KOLASA | 13 | Grantham | 5:42.00 |
| 5 | 26 | Annie WEBSTER | 12 | Grantham | 5:37.00 |
| 6 | 27 | Mia PARAPIJONAVICIUTE | 15 | Grantham | 5:30.00 |
| Heat Number - 6 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 28 | Grace HOWITT | 15 | Grantham | 5:28.67 |
| 2 | 29 | Lexie SHEWAN | 14 | Grantham | 5:28.25 |
| 3 | 30 | Amelia HATHWAY | 15 | Grantham | 5:26.45 |
| 4 | 31 | Annabelle JAY | 13 | Grantham | 5:26.43 |
| 5 | 32 | Amy TAYLOR | 13 | Grantham | 5:21.32 |
| 6 | 33 | Harriet MCCORMACK | 15 | Grantham | 5:16.45 |
| Heat Number - 7 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 34 | Ellena HOWITT | 13 | Grantham | 5:13.56 |
| 2 | 35 | Sophie WARD | 15 | Grantham | 5:08.33 |
| 3 | 36 | Ben CARLYLE | 14 | Grantham | 5:05.39 |
| 4 | 37 | Lucy WILLATTS | 13 | Grantham | 5:00.70 |
| 5 | 38 | Isla GRAY | 14 | Grantham | 4:52.67 |
| 6 | 39 | Elena ALDENHOFF-KELLY | 16 | Grantham | 4:45.70 |
| Heat Number - 8 |
| Lane | Comp.No. | Name | AaD | Club | Time |
| 1 | 41 | Daniel DEGNAN | 16 | Grantham | 4:34.60 |
| 2 | 43 | Jacob FISH | 15 | Grantham | 4:29.86 |
| 3 | 45 | Owen HATHWAY | 18 | Grantham | 4:17.40 |
| 4 | 44 | Joshua CLARKE | 16 | Grantham | 4:17.77 |
| 5 | 42 | Zach HOPKINSON | 15 | Grantham | 4:30.77 |
| 6 | 40 | Grace TURNER | 17 | Grantham | 4:36.12 |