res top off and fill up ?S

sparks662

Active Member
ok so im about to start my grow imitating the al b. fuct style and i have a few questions about setting up the res. i know what ppm im supposed to set all 4 res. to and im supposed to be replacing the nute soln every 2 weeks. my questions are how much nutes do i put in the res to get the right ppm, and how do i do top offs till my next 2 weeks refill? im using 3x3 flood tables and 18 gal. resoviors. thanks guys
 

santeelocal

Active Member
You mix your nutes according to the manufacturer in a seperate container, then you slowly add the soup to your res until reach the desired PPM, as for the topping off you add more soup if your PPM drops and more water if it rises.
 

UrbanAerO

Active Member
I do differently because I use 5 gallons to every 10 plants, I premix with my nutrient schedule 5 gallons for every aerobox, then as water is absorbed the PPMs rise. Every two days I go into the tent with a hose siphoning RO water into the rich mixture. when the rezzy is full the PPMs are exactly where I put them on the first day minus a couple hundred PPM. I basically add RO water to lean my nutes out, also helps with root lockout. I completely change out my nutes every week and in between nute changes I run pure RO water for about 6 hours or even all day. I think the flush inbetween nute changes really helps the plants strive and get ready for the next week of nutes.
 

researchkitty

Well-Known Member
If your PPM goes down and pH goes up naturally, then congrats. Your plants are using the water/nutrients properly. When they use the water, you can refill it as you asked just fine without emptying. If you add 10 gallons of water, add the proper amount of nutrients too. (aka 10 gallons @ 5mL/gallon of nutrient A = 50mL).

Tips:

-- Think of water as PPM down. If its too high, just add water.

-- Top off your reservoir every few days

-- Only add nutrients once a week, not every time you top off the reservoir.

After a while you'll just "know" what your plants eat, and "know" how much nutrients and water to add each time. It gets to be pretty routine.

Good luck!
 

Anonymouse

Active Member
I agree, keep your water level consistent and when doing fills, don't add nutrients. While your water will evaporate, the nutes will not.
 

DivinePower

Well-Known Member
Just curious as to why everyone says not to add nutes back in? Though I'll agree it shouldn't be done EVERY time you add water - if you see that your plants are eating the nutes, why wouldn't you add them back? Like today... I added water - checked the PPM and it was down from a couple days ago when I did the res change. I added in the nutes I wanted back in there and now I'm back to my target PPM. Smidge higher now because of the pH down... but that's no worry to me.

To each their own - but if my plants eat it... I'm going to add it back and make it available to them.
 

UrbanAerO

Active Member
I dont add nutrients during the week because I am going off a weekly schedule. Every week I completely empty, clean and refill nutrients. Water evaporates during the week and PPM's rise(sometimes over 2000PPM) so I just add water until the week is over then I start with. If the PPM is too high your roots will get clogged with salt and nutrient build up and not uptake anymore nutrients. If I notice a stunt in growth from this root lockout I will begin a couple day flush with clearex to dissolve salt build up.
 

Anonymouse

Active Member
It's also good to remember your grow medium will also have nute/build-up on it and it can be rinsed back into your res. Best thing, is to pay attention to the plants, if they don't like it you'll see the burn on the tips/edges and then you can back off a little.
 

fatman7574

New Member
Top off your water daily and adjust the pH daily. Check the EC daily. If your EC drops appreciabbly add enough nutrients to raise your EC. This means using a pH and a conductivity meter. This can all be automated but at a substantial cost.

Some without EC meters just mix up extra nutrient solution at 1/4 strength and use this to top off their reservoirs between changes.
 

DivinePower

Well-Known Member
Thanks for chiming in fatman - I wouldn't consider myself an expert like you, but I'm definitely no dummy either! :weed:
 

researchkitty

Well-Known Member
Just curious as to why everyone says not to add nutes back in? Though I'll agree it shouldn't be done EVERY time you add water - if you see that your plants are eating the nutes, why wouldn't you add them back? Like today... I added water - checked the PPM and it was down from a couple days ago when I did the res change. I added in the nutes I wanted back in there and now I'm back to my target PPM. Smidge higher now because of the pH down... but that's no worry to me.

To each their own - but if my plants eat it... I'm going to add it back and make it available to them.
The reason you add water on a day to day or every other day basis is because it evaporates. Nutrients dont evaporate. Its more of a logistics thing really, though. Consider the water the plants drink up and the water that evaporates. If it evaporates faster than the plants eat up the lost waters ppm of nutrients, then your ppm will go up. That's not good for some stages of the plant. By adding nutrients on a weekly basis, it allows you to monitor the ppm better to ensure the plants are actually eating. When the PPM drops by about 10-15% is when I'll add back nutrients and add them back to the level of the charts recommendation for whatever week the addback is done during.

It's also good to remember your grow medium will also have nute/build-up on it and it can be rinsed back into your res. Best thing, is to pay attention to the plants, if they don't like it you'll see the burn on the tips/edges and then you can back off a little.
You wont experience this whatsoever with Hydroton. There is never nutrient buildups at all since the system auto flushes every watering.
 

fatman7574

New Member
Just curious as to why everyone says not to add nutes back in? Though I'll agree it shouldn't be done EVERY time you add water - if you see that your plants are eating the nutes, why wouldn't you add them back? Like today... I added water - checked the PPM and it was down from a couple days ago when I did the res change. I added in the nutes I wanted back in there and now I'm back to my target PPM. Smidge higher now because of the pH down... but that's no worry to me.

To each their own - but if my plants eat it... I'm going to add it back and make it available to them.
There is really nothing wrong with adding nutes back to a recirculating reservoir system as long as you realise your are adding all nutrients to the reservoir not just those used nor in the proportions they were used. Many minerals are tied up daily as pH buffers thereby becoming non available to the plants. Topping off with nutrients helps to assure these minerals are still avialable. The only concern really with topping off is that people often do such only to avoid making reservoir nutrient changes. Not changing the nutrients regularly and topping off instead and leave to bad nutrient inbalances causing some nutrients to prevent others from being available. Once just needs to find a medium ground. With recirculating reservoirs I always did top offs of both water and nutrients, rather than just water top offs and changes. I always used frequent changes though rather than large reservoirs.

A too high EC does not cause a plant's roots to become clogged with excess nutrient salts thereby slowing uptake of other nutrients and a slowing of growth. A too high EC will cause different problems depending on the ratio of the ingrediants. It is not so much to too high EC that causes the problems but the skewed ratios of nutrients. IE too much nitrate means nitrogen burning, too high calcium means decreased nutrient uptake because it lowers water uptake, too high potash causes a high tranpiration rate but also decreases nitrate uptake. This is more of a problem with inbalanced fertilizers from the orginal mix or due to nutrient top offs more than a too high EC problem.

You also need to realise an ppm reading given by a EC or TDS meter is not a true ppm reading. It is only an approximation. A true ppm is based uopon the weight of each salt in mg per each liter of nutrient solution. Those ppm measurements are what the manafacturers state you will receive if you mix according to their directions. If you mix according to their directions and then use an EC meter on the new mixed solution the reading the EC meter gives you will not be the actual ppm, but will be lower. Sometimes much lower.

Personally when I used recirculation reservoirs I used 24/7 automatic water and nutrient top offs and pH balancing. Look up cooling tower controllers on eaby. They will control the pumps/soenoids/pinch valves for pH control and nutrient top offs. Leveling devices for automatic top offs are sold on about every reef aquairium on line store. I used many Hach GLI analyzer/controllers with two peristaltic pumps for pH adjusting solutions, a peristaltic pump with two pump heads for nutrient solutions and a Crouzet water level controller and peristaltic pump for water top offs. They ran many times per day and allowed very little flucuations. Now everything is drain to waste except clone cuttings being rooted and back up mother plants.
 
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