Topping up the nutrient mixture

As I understand it you should top up your resivoir every other day with fresh ph'ed water and the inbetween days with half strength nutrient solution. It would be just the same then if I just topped up everyday with quarter strength nutrient mixture?

If so I was thinking about putting a float valve in my res connected to a container full of this quarter strength nute mix so that it will keep itself topped up - does anyone see any problem with my method?

Thanks

"should" be fine. All comes down to PPM(tds) and PH.
without meters, you can only guess.
The plants will not always eat the same nutes at the same rate, which could cause your mix to get out of balance and have PH/PPM problems (which are hard to fix without meters, or a res change).

Yeh that is interesting i was looking at installing one of these float valves with a spare res myself. Does anyone have any diagrams or pictures of one set up?

Al B Fuct has a post showing a system he uses for vacations. And Mogie has a post, very detailed, showing how to accomplish this. Its more than likely posted in FAQ. VV

when i top up my resivor, i add the same solution as what's in there. topping your res constantly 1/4 str nutes will lower your ppm's, if thats what you want... great. i like to up my ppms. as far as topping up every two days, why do that, only if you have to/want to? thats worse than having to water soil every three days... hydro is susposed to be less maintenance. you let that resivor clear out and then refill it and you won't have very unbalanced nutes either. just dont let it get too low or you'll burn your pump.

russ0r said:

when i top up my resivor, i add the same solution as what's in there. topping your res constantly 1/4 str nutes will lower your ppm's, if thats what you want... great. i like to up my ppms. as far as topping up every two days, why do that, only if you have to/want to? thats worse than having to water soil every three days... hydro is susposed to be less maintenance. you let that resivor clear out and then refill it and you won't have very unbalanced nutes either. just dont let it get too low or you'll burn your pump.

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Russ, as I understand it, the plants use some nutrients and lots of water and leave other nutrients behind causing the ppm of the mixture to change this creates a need for res maintenance, tell me if i'm wrong though because the last thing I want to do is needlessly fuck around with my solution but I thought this was necessary

If you have a nutrient meter, then you will find the levels you want to keep the nutrient levels at. The plants take more water than nutes, so keep it topped up and at the desired nutrient level

GreenGro said:

the last thing I want to do is needlessly fuck around with my solution but I thought this was necessary

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I wouldn't muck around with topping up nutes between tank dumps. You should be dumping and cleaning tanks every 2 weeks. A tank of freshly mixed nutes will not be totally depleted in 2 weeks. Adding more in between dumps is wasteful and invites nute burn.

You WILL be able to watch the ppm steadily drop as the plants eat the nutes. I start at about 1300-1500ppm. I top with plain tap water and adjust pH as needed to keep it between 5.3 - 5.8. After 2 weeks, the tanks will drop to 800-1000ppm.

I guess it a preference thing, you dont want to be mucking around blind with nutes thats for sure, but me personally i would prefer to keep my tank at the optimum ec level making sure the plants are getting everything they need and not going short and keep a tank for longer to save cleaning it out so often and use filters on the pump.

ngt, I've discussed this with the rep from Canna. They reckon that there's about 40-60% of the necessary nutes left at the end of 2 weeks, but the plant takes what it wants; this alters the ratio of the nutrients to each other.

If you top up with more nute mix and only gauge what you're adding by the ppm (a very rough indication), you may have a 1500ppm solution, but with less N or P than there should be in relation to the other nutrients. You can't easily tell if there is an appropriate ratio with most home metering gear. This is why they discourage topping up with extra nutes between dumps.

This Cannafella impressed upon me that consistency of nute strength and NPK balance is important for getting consistent good results. The best way to achieve this is changing up about every 14 days with no top ups between.

I dont doubt that it is probably better for the plants and I have no arguement against your experience or knowledge, im just too lazy to do tank changes every 2 weeks.

nongreenthumb said:

im just too lazy to do tank changes every 2 weeks.

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Oh, well.. that's OK then!

I can guarantee you I hate tank changes as much as you do, if not lots more... so I added some lawn irrigation valves and some bits of garden hose to make the tank dumps as easy as possible.





Twist two knobs & hit the pump... a cup of coffee later, the tanks are drained and ready for fresh sauce.

Al B. Fuct said:

This Cannafella impressed upon me that consistency of nute strength and NPK balance is important for getting consistent good results. The best way to achieve this is changing up about every 14 days with no top ups between.

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This means not topping with plain water or anything then Al?

Thanks all!

Top tanks with plain water only. Adding tap water will usually drive the pH up a couple of tenths. Adjust pH of the solution in the tank as needed. No need to add more nute mix.

Al B. Fuct said:

ngt, I've discussed this with the rep from Canna. They reckon that there's about 40-60% of the necessary nutes left at the end of 2 weeks, but the plant takes what it wants; this alters the ratio of the nutrients to each other.

If you top up with more nute mix and only gauge what you're adding by the ppm (a very rough indication), you may have a 1500ppm solution, but with less N or P than there should be in relation to the other nutrients. You can't easily tell if there is an appropriate ratio with most home metering gear. This is why they discourage topping up with extra nutes between dumps.

This Cannafella impressed upon me that consistency of nute strength and NPK balance is important for getting consistent good results. The best way to achieve this is changing up about every 14 days with no top ups between.

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Al I have been thinking about this since you posted and I appreciate you and the canna rep know a damn sight more about this than me but my thought is this:

As the plant takes what it wants of the nutrients there could be a load of N left at the end of the week and not enough P for example, if this was the case then wouldn't adding more nutes increase the amount of P so the plants have enough of it - If you don't add more nutes and most of the P was used up the plant would be getting less than it wants. As for the ratio of nutes being altered, well if the plant only takes the nutrients that it wants then this should not matter.

What do you think?

Thanks again

And further to that last post - if canna have their nute mixes right then the plants should use the nutes in more or less the correct proportion, no?

I suspect that how much of a particular nutrient a plant uses has much to do with the particular phase of growth. GH 3-part nutes recognise that by giving the grower a broader number of mixing choices. Canna nutes are typical 2-part, with no alternate mixing instructions for certain growth phases, just equal amounts of 'A' and 'B'. Thus, Canna Flores has to be right- or close to it- for a broader range of plant needs without grower intervention- or it's wrong more often than GH.

GreenGro said:

As the plant takes what it wants of the nutrients there could be a load of N left at the end of the week and not enough P for example, if this was the case then wouldn't adding more nutes increase the amount of P so the plants have enough of it

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Yes- if you knew which to replace, you could do that.

However, all most mere mortals in the grow room have is a ppm meter- not a mass spectrometer. You know the 'total dissolved salts' figure, but you can't tell if there's more or less of any given element without sophisticated measurement devices.

If you're that far into it, you should be mixing your own nutes and selling them!

Al B. Fuct said:

Yes- if you knew which to replace, you could do that.

However, all most mere mortals in the grow room have is a ppm meter- not a mass spectrometer. You know the 'total dissolved salts' figure, but you can't tell if there's more or less of any given element without sophisticated measurement devices.

If you're that far into it, you should be mixing your own nutes and selling them!

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Fair enough, I understand that you wont know which nutes need replacing and by how much but would it be better to add more of all of the nutes than say the possibility of not having any of a particular nute?

Al B. Fuct said:

ngt, I've discussed this with the rep from Canna. They reckon that there's about 40-60% of the necessary nutes left at the end of 2 weeks, but the plant takes what it wants; this alters the ratio of the nutrients to each other.

If you top up with more nute mix and only gauge what you're adding by the ppm (a very rough indication), you may have a 1500ppm solution, but with less N or P than there should be in relation to the other nutrients. You can't easily tell if there is an appropriate ratio with most home metering gear. This is why they discourage topping up with extra nutes between dumps.

This Cannafella impressed upon me that consistency of nute strength and NPK balance is important for getting consistent good results. The best way to achieve this is changing up about every 14 days with no top ups between.

Click to expand...

I've been thinking about this since my last comment.

I think that you should take your nutes to a longer period and top up with nutes and keep the tank at the right level for ec and ph and water.

This "cannafella" or the rep from canna as you have put it both times, is exactly that a rep.

He is a salesman, this is his job.

I'm currently running 3 120 litre nutrient tanks, so thats 360 litres of solution.

Now my nutrient says to make full strength solution you add 7ml per litre so 360 x 7ml = around 2.5 litres.

My boost says to use 7ml per litre also = 2.5 litres

Add the nytrozyme 1ml per 10litre = 36ml.

there are other macro nutes that i use also but we just base it on this for now.

a 2 litre bottle of the nutes i use costs around 20 usd
a 2 litre bottle of boost is 20usd
50ml of nytrozyme is 10usd.

so in total this adds up to 60 dollars.

now i can see why the canna rep is getting you dump all that every 2 weeks.

60 DOLLARS ON NUTES EVERY 2 WEEKS

you must either be selling plenty and making enough money not to realise or care or you just got money to burn