please can u help with this

Hi guys after reading many threads and reading certain books i really need a little help, Me and friend decided to build our own sort of nft system now everything is working ok pump hose is connected great 1st week we got clones i put them streight under light they had already been veged by friend for a week or so just going into 3rd week of me having them and i have purchased vitalink nutes and i followed the guide on back i think i may have added too much at the start so i bashed up a new mix

water from tap filled a 16 litre res added nutes got ph down to 5.9 also checked the ppm which was 716 ec just above 1.0 heat is always about 70-75 and they are in rock cubes and for 1st 2 week we didnt have them covered we just had the 4 sat in tray under light but roots were every where underneath even trying to break threw sides so we finally put them under the cloth mow every night about this time onwards they either look stoned or tired like this in pics can any 1 help here's some pics

View attachment 2910819View attachment 2910820View attachment 2910821View attachment 2910822View attachment 2910823

not sure if this helps when i 1st got them i was told 24 hour light for veging but after reading and trying to learn i switched them after 1 week to 18/6 now the strange thing is when i switch the light off at 4am they look like that in pic but when i get up in the am and switch back on at 10 they are bouncing and leaves always looking good see what im really concerned about is when i got them the blocks were light but when i put them under the mat the blocks were as heavy as hell and i dont had to feed them for like 4 days all they have had is pump run for 4 mins today im really a noob and i no my setup aint cool its proper jalopy style but with the money i save from paying money for crap bud i can buy myself a really cool system but for now this will hopefully work sorry about lack of punctuation and picture quality only got my nexus 4 i like to thank u all now for any help i may get and also for all the help i have already had from reading posts

I get the feeling a ppm of 716 might be a little high for such small plants, I would lower to abt 400 to 500 'till they get a little bigger, tho 5.9 ph isn't that bad I would drop to 5.8 (the ideal ph in my book) seems to me that a diff of .1 is greater than one thinks, I'm not an expert but it seems to work for me.

thanks bud i will do that try 400 if sits well but would u say i should water them or let them dry some more thanks

I would probably let them dry, I once fed just water to my hydro plants once and they drooped pitty bad immediately after, so I gave them a lower ppm of nutes right away and they perked up, I don't think it's a good idea to feed just water with hydro plants, that's just my opinion based on observations.