Strawberries wilting

[Twilly]

I planted some strawberry plugs about a month ago... They took forever to start growing ( only 3 of 10 plugs grew )

I have 3 leaves on each plant and things were starting to look good... But now the leaves are turning brown? They are in a DWC system, the water level is about a quarter inch over the bottom of the net pots, I am using GH MAX dry nutes ( 1 tsp per gal ) PH is 6.5. I change the water every 2 weeks, and I have tomatoes in another system that are only 2 weeks old and are taller than the strawberries. What am I doing wrong?

Thanks

Twilly