TheBioMaster said:

I should have mentioned, not ALL nutrients have ample amounts of cal/mag and do need the dreaded plant killing supplement.

I also should mention I ran a business that tested nutrients for various reasons from determining dosage rates, to getting testing done for label registration in various states.....companies you may of heard of like Dyna-Gro.

I have yet to test nutrients that required cal/mag. I obviously haven't tested them ALL, but I would say most all.

That being said, ill tell ya a secret..... Most supplements are created because of a market demand. That means simply it was guided by growers in the field as opposed to scientists in labs. You can take that to mean what you like......but most interpret that to mean a lot of supplements are simply not needed.

One other thing I noticed about nutrient makers is that none did any actual scientific research at all except for Advanced Nutrients. Most nutrients companies don't even make their own nutrients...... Like the UC nutrients for example.

Unless you are a chemist, following the guidelines of a nutrient company like Advanced that recommends using RO water and changing your solution out every 7 to 10 days is HARDLY ancient advice....lol

Like I said.....trying to reinvent the wheel.

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Aqua Man said:

Absolutely will reduce the need for frequency of top off and res changes. Also will provide a more stable ph and ppm. But will use more nutrients.

Do a water change based on add backs. Once you have added back the volume of water equal to the ACTUAL water volume of the system. Then do a water change. In early stages you may go 3 weeks or more without a changeout and mid flower maybe once a week. This helps cut back on unnecessary water changes. The reason is the less they take up the less change in nutrients ratios. So you can just steer the res with top ups to get your ppm and ph and your adding back proper ratios so each top up help bring the ratios back towards balanced and if you change the res after your add back equal the volume then you should never have an issue with ratios going to far out as to create an issue and like I said in the earlier stages you save a lot of wasted water changes.

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TheBioMaster said:

Wow! I been running RDWC for 10 plus years now......and NEVER do any of that! In fact it kinda confused me! LOL!

1. Change your tank every seven days.....

2. Don't use cal/mag

3. Use RO water

Done.

There is no "top up" needed or used in RDWC. You have a epicenter, and a res tank, with a proper system. Your not "topping off" anything.

Until I adopted this method, after YEARS of system design changes trying to fight the problems.....everything fell into place.

It amazes me to see people reinvented the wheel over and over with these attempts at detailed instructions and explaining..... When nothing could be easier really......

Good luck with your topping off and what not.......

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Aqua Man said:

Thats all great but not much has changed drastically in nutrients over decades and im not sure how it pertains to top ups. Testing nutrients for companies doesn't change anything on the matter of tops ups and how ratios can change based on uptake...no uptake very little change lots of uptake much more change in both ratios and ppm or are you denying that? Yet we should treat it the same? Water volume is a huge factor enough volume you won't even need to change it but thats unrealistic and in a small volume you definitely need to change it more often... not sure how your experience changes that?

I mean hey if you wanna throw away 50, 100, 200 gals of water a week for seedling have at it... its not my $$$. Wanna see someone in mid flower in a 5 gal pail do weekly water changes and no top ups... what you are talking about is assuming everyone has your system. This addresses all systems and is intended to cut out the huge waste early on while still meeting the requirements of later in the grow. Plants change needs I have no idea why you think otherwise? I mean its pretty clear to see in mid flower the drink and eat a shit ton more than a seedling but hey if its not for you its not for you.

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Hazyboy said:

So I came across this thread after running into some issues with my exploration of hydroponics.

I've basically been following aquamans recommended procedures for doing top ups before I even saw this thread. I monitor how much PPM they eat each night, adjust my top up accordingly and get my PPM back to the original target.

Twice now I have ran into nitrogen toxicity. My initial thought when this happened is that my plants are eating different nutrients at different paces, therefore when I top up nutrients in their original ratio, some are being added which are not needed.

I'm currently using (in flower)
Micro
Calmag
Bloom
Bloom boosters
And in veg I'm using grow instead of blooms

Both times I've experienced this, I have been around 3 weeks into flower. At this point I'm assuming that the calmag and micro is being eaten much slower than the Bloom formulas and my ratios are out to lunch.

Does anyone have experience with issues like this? Does anyone know if the plants will be able to recover from nitro toxicity? How can I adjust my top ups without knowing exactly which nutrients are being eaten and which ones are not.

I've out a lot of effort into making hydroponics work at this point but I'm getting frustrated and considering going back to coco.

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Aqua Man said:

If you do a complete changeout after adding back the volume of water of the system as top up it should keep ratios well within balance.

What nutrients are you using and at what ppm?

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Hazyboy said:

What do you mean by doing a complete change out after adding back the volume of water? I don't quite understand.

I'm using Remo nutrients for my
Calmag
Micro
Bloom
Grow (in veg)

Future harvest (Bloom boosters)
Mid flower
Bud boom

Green planet
Root builder (beneficials)

My PPM right now at 3 weeks is about 500.

My current mix to achieve that is
Calmag 3ml/g
Micro 4ml/g
Bloom 3ml/g
Mid flower 3ml/g

When I top up, I use the same ratios but adjust the amount based on how much PPM my plants ate over night.

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Aqua Man said:

So even with top ups you need to do complete water changes... if your system holds 20g of water (actual water not container size) then after adding back 20 gal you empty the system and make a fresh res. This is done to ensure ratios are kept in check as plants don't always take up nutrients in the ratios we give them. Plus the exude compounds from the roots that may skew the ppm and makeup of it

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Hazyboy said:

Right, I do a complete water change every 10-12 days during flower typically.

My entire system hits the full mark at about 82 gallons right now. It's the top ups between those res changes that seem to be the issue. Each loop drinks around 8 gallons per night at the moment (3 weeks into flower) I top up that 8 gallons with nutrient strengths based on how much PPM they ate over night, which has been around 30-50ppm on average.

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Aqua Man said:

Shouldn't be any issue... unless the ppm is to high... say if running low humidity they will drink a lot more so need to run even lower. I never had to run more than 600ppm in my systems and that's with co2.

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Hazyboy said:

I'm at a loss man, I've put a TON of research and time towards this. I'm an experienced grower with a good handle on the science, I've done really well with many other mediums on both large and small scale.

My room is pretty dialed, VPD is literally perfect, co2 is 1000ppm. When one of my loops was 11 days old my plants started showing obvious signs of nitrogen toxicity, and this is the 2nd time its happened. Both times it's occurred, it happened right around the 3 weeks of flower mark as the res got older. My guts telling me the micro and calmag are too abundant in that old res. My veg cycles have been amazing, the plants are so healthy and growing way faster than I could ever imagine.

Maybe I should try some new nutrients, whats your feed schedule look like?

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Aqua Man said:

Have pics? Just wanna make sure it is tox.

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Aqua Man said:

Do you have an IR temp gun to check those upper leaf temps?

Just to cover my basis what are the room temls and humidity?

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