Res Tank Top Offs

Ok boys and girls here is a topic Id like to hear more thoughts and pros and cons for.I was thinking last week after reading some post.I saw few either way pn this but want to see more and reasons why. Some say its fine to top a res off with more ph balanced water others say dont as the nute strength will be off and you wont know which nutes are off maybe the nitrogen maybe the phos.I can understand this but to those who dont top off with fresh water how do you control the ppm rise rate?Alot of times my plants will drink more plus evaporation in an aero setup which can cause the ppm to go from 1400 to 1700 how do you bring the ppm down without topping with water? Lets see what people say..Thanks

That's a good question?Iwant to here what everybody take on this. PEACE

Yeah, good question, but I don't think that you'll get much discussion cause most folks just know a little about it.

First you have to specify whether chemical or organic nutes. Most hydro growers use chemical, since hydro-organic requires some experience.

I'll just say that when using organic nutes, you can top off with plain water or a weak nute solution or a reg-strength solution, depending on your res maintenance method, and leave it at that.

For chemical nutes, if you use a TDS meter, it's easy to see the daily rise in ppm with no topping off. When you add plain water, to raise the amount to original level, the ppm is close to the original level too.

Even if you don't measure ppm, it's easy to maintain a res. When you mix a new batch, just mark the full line of the res. When you maintain the res, just fill with plain water to the full line. When you've added back the same amount that the res holds, it's time to change the res.

HTH

potroast said:

Yeah, good question, but I don't think that you'll get much discussion cause most folks just know a little about it.

First you have to specify whether chemical or organic nutes. Most hydro growers use chemical, since hydro-organic requires some experience.

I'll just say that when using organic nutes, you can top off with plain water or a weak nute solution or a reg-strength solution, depending on your res maintenance method, and leave it at that.

For chemical nutes, if you use a TDS meter, it's easy to see the daily rise in ppm with no topping off. When you add plain water, to raise the amount to original level, the ppm is close to the original level too.

Even if you don't measure ppm, it's easy to maintain a res. When you mix a new batch, just mark the full line of the res. When you maintain the res, just fill with plain water to the full line. When you've added back the same amount that the res holds, it's time to change the res.

HTH

Click to expand...

I trust your opinion and I respect it more than a lot of the others on here.

Going from what you have just said then, would it be ok to keep a nute tank running for 4 weeks and topping up with water or nutes to keep it constantly at the desired ppm level or would you advise me to just top up with water for 2 weeks and then dump the tank with all the nutes in and start fresh so the ratios are more evenly balanced, would dumping every 2 weeks provide that much better results.

potroast said:

For chemical nutes, if you use a TDS meter, it's easy to see the daily rise in ppm with no topping off. When you add plain water, to raise the amount to original level, the ppm is close to the original level too.

Click to expand...

Depends on the size of the rez and the number of plants it is supplying- and that's a rather inexact science. On-the-job-training will reveal a lot, tho.

If the tank size is fairly closely matched to the usage requirements of the batch of plants it is supplying, as water level drops, the ppm will remain close to the target ppm for a fresh tank. If such a tank is topped up with plain water, the ppm will drop, corresponding to the nutes depleted from the solution by the plants.

If the tank is somewhat too small in volume for the plants' water usage requirements, ppm may rise a little as the plants use the water. In that case, adding plain water to the tank will return the ppm close to the mix target, although ppm will drop a little according to what the plants have eaten.

I have both situations; my mother system has a ~50L tank, but at the moment is running 10 bushy mother plants which suck a lot of water. The nute ppm rises as water level drops. If the tank volume were greater, the plants would use a smaller percentage of the tank volume each day and the ppm would not bump so much. I'd use a bigger tank there if it would fit under the tray.

My flowering systems, each running 125L tanks and supplying ~20 plants each, seem to maintain ppm within about 5-10% of 1500 for a week at a time, depleting about 25-30% of the volume of the water in each tank. Means the nutrient consumption is very close in % to water consumption.

I'll go with whatever potroast says thanks al, i trust his judgement.

ngt, the sky is blue.

nongreenthumb said:

I'll go with whatever potroast says thanks al, i trust his judgement.

Click to expand...

Great- glad you agree with me.

What I wrote concurred precisely with what potroast said and expanded upon it.

I gave you the blue sky bit so you could have something I said that you would be sure to disagree with.

Your trying to make this some kind of competition, but i couldnt care less and your not going to wind me up.

I trust in what potroast says. You I couldnt give a toss about but hey ho.

nongreenthumb said:

I trust your opinion and I respect it more than a lot of the others on here.

Going from what you have just said then, would it be ok to keep a nute tank running for 4 weeks and topping up with water or nutes to keep it constantly at the desired ppm level or would you advise me to just top up with water for 2 weeks and then dump the tank with all the nutes in and start fresh so the ratios are more evenly balanced, would dumping every 2 weeks provide that much better results.

Click to expand...

Hey, thanks Bro! My response just summarized some basic res maintenance, and Mr. Fuct's answer goes into what really matters, the size of the res, and how much of it is used for each irrigation. The larger the res compared to what is used, makes for more consistency in strength and pH.

So for your situation, how big is your res, and how much of it is used to flood? How often do you top off? Do you measure TDS?

The easy way is to mix a fresh res on a regular basis, that way you know that your plants are always well fed.

HTH

potroast said:

Hey, thanks Bro! My response just summarized some basic res maintenance, and Mr. Fuct's answer goes into what really matters, the size of the res, and how much of it is used for each irrigation. The larger the res compared to what is used, makes for more consistency in strength and pH.

So for your situation, how big is your res, and how much of it is used to flood? How often do you top off? Do you measure TDS?

The easy way is to mix a fresh res on a regular basis, that way you know that your plants are always well fed.

HTH

Click to expand...

each one is 120 litres, i top off with plain water or nutrients and keep the e.c at the right level. every 4 weeks i tank change, but al says this no good

Kinda getting to what I find myself.My res is a 50 gallon res which I keep at about 30-35 gallons in it for 28 plant system.I find in flowering they drink alot more water as I have to replace approximately 6 gallons ever 1-2 days and the ppm jumps pretty fast if I dont.I started it at about 1400 but I tend to have to top off with plain water as I test before with the 6 gallons down and the ppm is around 1700.I add the water back to the original level and get the ppm back to around 1500.I find for my ppm to drop it takes about 2 weeks of this retopping with plain water to get the ppm down to 1000 or so then AAt about 2-3 weeks Ill completely drain again and do fresh.I use Fox Farm grow big, tiger bloom, big bloom, and Botan.. Sweet berry..Another related question Id like to hear from Al on is when you check your ppm do you start from the plain water ppm or go into additon to the starting ppm ie if plain water is a ppm of 400 and your nute schedule calls for a 1400 ppm count do you go up 1400 nute ppms to total 1800 or do you start at the 400 ppm and add another 1000 ppm of nutes and hit 1400.

Ok, so let's talk about the both of you. FF and NGT both have a res with about 30 gallons. But NGT didn't answer the most important question, how much of that 30 gallons is used for a typical flood.

I'd say that in FF situation, that most of it is used to flood because he has to top off with so much every day. If you are topping off with 6 gallons, then you should change the res after 5 top-offs. Since you are monitoring ppm, you have to top off with nute solution, either full-strength or partial, to keep it right. What Al is saying is that the soup becomes umbalanced. Even tho your ppm meter shows everything is in line, it may not be. So why risk some loss in yield, or worse, just to save some nutes?

Nutrient ppm is in addition to your starting water ppm.

HTH