Zero reservoir change Lucas Formula?

I'm on week 8 (3 of flower) on one group, week 5 (about to flower) on another, and both have never had the reservoir changed. I'm experiencing no issues with either group and just started group 3. The reason for doing so is rather simple- I'd read a thread that Lucas had participated in that said he now believed this was the way to go; that while you'd anticipate nutrient shortages and overages, this doesn't seem to be the case and that the plants are perfectly happy under a full grow cycle with never changing the reservoir. This makes a huge impact on the nutrient budget. Root zones are happy, leaves are happy; no signs of nutrient deficiency. I keep the reservoirs at 1000ppm using micro and bloom at 1:2; pH is rock steady at 5.9 in both and I rarely have to adjust the pH. I've been through roughly just under 1/2 qt of micro and nearly a quart of bloom so far on the entire crop. Does anyone else do this? I've mainly become worried because with a slew of rulings from the court this week on dispensaries and sales, there isn't a reliable source and this crop just became very important.

Yah mon, I do it the same way and the plants look great. Seems like a no brainer to me if not having any other problems. Definitely saves on the nutes and a lot less trouble also.

Peace.

Vhampyre: if it ain't broke don't fix it. That's not the way I do it but it doesn't mean it's wrong. Let nature takes its course and fill us in on the end results. We might all learn something. Just make sure you document everything so we can replicate your experiment. Hank

Very Interesting!

Thanks for sharing.

I'll keeping going; HSA makes a good point with not fixing it if it ain't broke. About the only other vital statistics for those interested are that I'm vegging under CFL's in a grow tent, they're flowering under 400W HID (Freebies from a retrofit to flourescents at work- a HPS is in the future). Keeping room at 75 with it's own A/C, dropping to about 70 at night. Humidity rock steady at 50%. Crop 1 is Aurora Indica (3) and 1 original Berry. Crop 2 is Berry x 3. I just moved batch 2 out into flower under it's own 400W HID today due to plant size. I have a limit of 7 foot ceilings. Room is vented, no CO2 gen yet (though I need to start a batch of homebrew beer soon!) I'll add pics in a few days of where it's at.

If you experience problems, consider changing the rez.

If the airstones/roots/walls get gunked up, consider changing the rez.

If you start to have mildew/unnecessary foam.. you know what to do.

Well, Void, the plan is that if any issues occur, pull the pump and air stones, scrub the res, replace the air stones, disinfect the air lines with h2o2, skip a pump for now at this stage (not using it for anything but samples anyway- the drippers are removed. I built the reservoirs so they have sample valves since I wanted it to be easy and to minimize chances of contaminating the res) and refill the res with fresh nutes/water and h2o2. However, I suspect that the issues won't occur as long as temps are in line and I keep garbage out of the res, in which case I'll continue forward with adding water, and keeping the nutes at 1K. If any deficiencies/etc show up, I'll also consider a res change. Barring that, though, the only planned res change is in the last week for a few days on pure pH balanced water for the flush. If it works, nute costs have dropped considerably. Basically, they're checked twice daily during "daylight"- once before work, and once after work. Excessive, since nothing's gone to hell yet, but still; as an experiment, better safe than sorry. So if anything goes to hell, the biggest variable and most likely cause should be my res- in which case, I'll change it out.

Official count; 8th week without changing the reservoir; I am happy with how things are progressing. pH steady at 6; at 1200 ppm. Room Temps are 73 at 54% humidity today, varies between 72 and 77. Humidity ranges from 48 to 58.

Bud pic is latest; images are date stamped.

Looking good for no rez change.

Any updates on the res change or harvest?

Nice plants I have some bucket dwc now that I am not going to change reservoir unless problems start to show, but I don't expect any. I will just top off with water and add nutes when my ppm drops below my normal range.

The op is over a month old.. and I'm thinking this thread is abandoned.

Could be maybe the pythium set in.. lol.

BigBuddahCheese said:

Could be maybe the pythium set in.. lol.

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Wouldn't surprise me.. I'm going to do a rez change rite now. It's REALLY important if you run organics.

i use GH flora/micro, never change res, always yield large

This thread is probably abandoned but for conversation sake I think you should at least change out your res when switching from veg to flower. I know you don't have to especially if your running a sterile res, but I still would. Personally I think changing your res every 2 weeks in veg and once a week in flower is just good practice which for me helps make sure that my ladies always have the essentials available. That's just my 2 cents though, good luck op and happy growing wherever you are.
KnB

kushnotbush said:

This thread is probably abandoned but for conversation sake I think you should at least change out your res when switching from veg to flower. I know you don't have to especially if your running a sterile res, but I still would. Personally I think changing your res every 2 weeks in veg and once a week in flower is just good practice which for me helps make sure that my ladies always have the essentials available. That's just my 2 cents though, good luck op and happy growing wherever you are.
KnB

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Ya thats a no brainer i am doing it just in veg then in flower on one plant with AN Sensi.

I'm flowering in week #4 right now with a 22 gallon DWC set-up. No reservoir changes AT ALL. In the first two weeks I had a huge problem with clear, snotty algae, and then the root rot after, but I brewed up some beneficial bacteria tea and haven't had a problem since.

Crazy set-up but it is working for me like a charm. Lucas Formula with GH, no reservoir changes, and I use beneficial bacteria. Whatever works for you.

Swiller said:

I'm flowering in week #4 right now with a 22 gallon DWC set-up. No reservoir changes AT ALL. In the first two weeks I had a huge problem with clear, snotty algae, and then the root rot after, but I brewed up some beneficial bacteria tea and haven't had a problem since.

Crazy set-up but it is working for me like a charm. Lucas Formula with GH, no reservoir changes, and I use beneficial bacteria. Whatever works for you.

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What kind of beneficial bacteria product you used?
I think I will try same method..

KaaPorridge said:

What kind of beneficial bacteria product you used?
I think I will try same method..

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This thread is from 2011, I doubt you will get a response.