ph problem in hydroponic system!!! please help!!!

hey cannabis.comhow we doing people, i have a bit of a ph problem that i was wondering if anyone out there could please help me with!!!! i'm 3 weeks away from harvesting and for the past previous 2 weeks i've been having a ph problem that i'm not shore how to fix, i am growing in a NFT hydroponic system my nuts are kept between 700 and 800 ppm TDS and i change the water in my res once a week, when changing the water in my res i ph my res water to a ph of 5.8 but by the following day the ph will drop to a ph of 4.5 which i then add some un PHed water to the res to up the ph of my res back to 5.8 again but shore enough by the following day the ph is back down to 4.5 which i then repeat the same process and i do know that a ph of 4.5 is not good for the plants, i think the problem is that my plants are drinking more water than nuts and are drinking nothing but the un PHed water that i've added to the res the night before which is why my ph drops so much and im worried that if this keeps happening im gonna corse a nut lock out or something so can some one please tell me how to stop the ph in my res from dropping so dangerously low to a 4.5 everyday as its starting to stress me out and corse me some unnecessary grey hairs!!! thanks for any help people!!!

You need to get some PH up, just water is not going to help. As you see it is very temparary. PH up will help stablize it. And check your ph and adjust as late in the day as you can, then it won't be as bad the nest day and your plants won't suffer the up and down locking out nutes.

hey loc nar thanks for the reply mister as it can hard to get a responce as most people just like to view someones comments without actually answering the question and what you have wrote makes perfect sence as ive been scratching my head for a while now and funny enough i said to myself today i wonder if ph up from a bottle would help in any way as ive never used ph up before as the guy in the grow shop said you dont need it as un PHed water from the tap works just fine but as you said its very temparary compared to ph up which you said will help stablize it so once again thank you for your time sir and il go get myself some bottled ph up!!!!

Don't forget a little PH down just in case it goes up too much and you need to bring it back down. It took me a little while to get the hang of it and I over did it a few times. I was in a hurry and messed up. So a little at a time till you know how much it will come up for your rez size. I guess I'm one of the last ones who learned a great deal from Zandor. He was always here and a great help to many. Glad I could make sense of it.

pH Up/Down are crucial for hydro. I've looked into other 'homebrew' ideas like vinegar and lemon juice, but they will make the pH fluxuate wildly. pH Up/Down are much more stabilized.
Good luck on your grow!