Ive been busy the last few days. We have been having a relatively warm winter, but that changed last week and this week with a ton (for us) of snow. You folks who have real winters will laugh, but 2" around here freaks everyone out, and we are supposed to get as much as 8" in some places My granddaughter and I love it, but she gets to stay home from school and I dont work
In between all the prep for the snowmagedon event, I managed to get a bunch done on the system:
1) re-plumb the accumulator tank so it sits vertically,
2) cleaned the accumulator tank a little bit. I didnt have time to do as good a job as I wanted, but I did get a good (bad) bit of nasty looking gunk out of it. It was brown and like thick oil and smelled nasty.
3) I replace most of the plumbing inside, and between the rez and the main pump.
4) I did a much better cleaning job on the rez.
As a result of all that - its clear my system is infected with nasty brown gunk/algae/slime/crap of some sort. It also seems very certain that that gunk is at least partially responsible for the PH rising. I am quite certain this is the main issue in the rez.
After cleaning the rez and replacing the most of the plumbing, and cleaning the rest as best I can, I did a new mix of AN nutes and RO water plus some CalMag. I did it to the same concentrations I did before, EC 1.0.
After that, the rez was holding PH longer than it did before the cleaning. The accumulator tank did better - actually much better, for about 4 hours or at least 4 times as long. It was steady at 0.1 higher than the rez, as compared to .5 higher before, but after 4-5 hours, the PH started going back up.
That got me to doing some other testing and checking.
First - It seems like if there is ANY air trapped in the hi-pressure parts of the system, that forces the PH up even faster. It want to stay up as long as that air is still there. I can tell because the water wants to fizz up when first drawn from the hi-pressure parts of the system. If there is fizz, then the PH is higher than if no fizz.
I did some testing in several places in the system and if there is air trapped in a filter, the PH is lower before the filter, and higher after the filter. Once I purge all the air, its reads the same on both sides.
Evey once in a while, I see this fuzzy water when I draw it from the accumulator tank - but not every time. If the bladder was leaking, it should happen every time. Plus Ive checked and I get no water out of the schrader valve, so Im pretty sure the bladder is not leaking.
So - where is that air coming from? Yesterday, I noticed a bunch of bubbles forming inside a mason jar of fresh RO water I had just drawn - lots and lots of bubbles. I am now thinking that when I re-fill the rez with fresh RO water, I must not be allowing enough time for the cold RO water to equalize and its outgassing after it gets into the tank and warms up. When that fresh, cold water gets compressed, it must be super saturating the water - driving the PH up.
That combined with the gunk is causing the drastic PH rise when the nutes get compressed.
The bottom line seems to be the gunk though.
Earlier today I did a second flush of the accumulator tank. When I "cleaned" it earlier, I connected it to my tap water through some hoses and valves so I could fill it with water, then drain it quickly, then re-fill and repeat. During the first fill, I put some dishware detergent inside the fitting before filling. The I let that sit for abit and started the flushing cycles.
But my house water pressure is only about 50 PSI, and the tank is per-presurized with 80 PSI of air on the bladder. That means I was not able to fully stretch the bladder or fill the tank very full at all. The bladder is textured or quilted or folder in some way. It looks to me like it has a million folds that can trap gunk and the tank would need to be filled almost full to stretch it out.
So, early today I filled it up to 135PSI with nute water and drained it a few times until the rez was empty. I got quite a bit more gunk out this time. Then I re-filled the system and spent some time trying to purge all the air out. Before the next grow, Im going to add more places to bleed air out, and try to eliminate places air can get trapped, to make it easier.
After all that, I re-filled the system. This time the rez and tank stayed about 0.1 PH apart for almost 6 hours instead of the 4 hours from before.
Now that the water in the tank has warmed up, it is somewhat fizzy again, and the tank PH is reading 5.9 while the rez is at 5.4 - back to the 0.5 PH difference.
BUT - here is the problem with all that thinking. Compressing extra C02 into the water SHOULD drive the PH DOWN - not up! One detail that supports that is the fact that the PH goes UP even more after the pressurized water sits long enough for the fizz to go away.
So, once again I seem to have results that are contradictory.
The one thing Im certain of is my system is contaminated. Im gong to have to address that no matter what - and it is probably the key issue in one way or another.
Im close to finishing this grow, so super cleaning will have to wait. Im just hoping I dont have to replace too much of the system. The 1/4" tubing and fittings are cheap, the accumulator tank, pumps and other parts are not.