• You are viewing the forum as a Guest, please login (you can use your Facebook, Twitter, Google or Microsoft account to login) or register using this link: Log in or Sign Up

Daily vs Weekly Dosing


10 Jun 2009
At the moment I dose using dry ferts.

I use Nutri Calc to work out the amounts I mix up. It is set up so that it calculates a week's dose for one application

I therefore only dose Macros on a Saturday, after >50% water change and add Traces on the Sunday. This is due to my forgetting to dose everyday :oops:

Would this be any different, results-wise, from dosing smaller daily amounts?
The general consensus is that daily/staggered dosing means nutrients are available at all times for the plants. Dosing weekly might mean by the end of the week nutrients are running low.
Are you running EI on a CO2 tank?
If you are then I agree wholeheartedly with Steves' comments.

I run my 160l tank no CO2, 1wpg T5, and weekly dosing shows no worse results than daily dosing on this tank.

You can always try either way to see for yourself... just be consistent and allow at least 3 weeks of each method so that you give it enough time to show up any differences.
plants grow well within a range, the range becomes too wide if you drive the lights higher, and dose only once a week, for example going from 30ppm, down to 5ppm, against 20-25ppm range. i am sure you will agree an average is better - also less chance of algae.
If you drop to say 5ppm, growth drops off by about 60-70%.
If you keep it at 20-30ppm, growth declines only about 5%.

a target of a constant 20-30ppm as you can see is a much better option

If your tank is low tech like Matts, weekly option might be ok as demands are much lower without CO2 injection.
Thanks for your replies.

I run DIY CO2.

My thoughts are that by dosing the same amount as I would in 3 doses, in a single dose, without WC through the week, that there would be same ppm at the end of the week.

But, if there is an abundance of ferts at the start of the week, would it affect the plants in that obviously there is a constant amount of light, and constant CO2(assumed due to DIY), with an ever decreasing level of ferts, in comparision to 'topped up' ferts from daily doses?

I would be interested in carrying out a trial run of daily dosing against weekly but I shall be upgrading to cannister CO2 next month so it wouldn't be a fair test.
Plants and most things adapt well to a range, vs fest of famine.
Plants use a certain set of enzyme that take up nutrients with a certain concentration range, say 1-5ppm of NO3, another set at 20-30ppm and so on..........or with CO2, they have plenty of Rubisco to scavenge every bit of CO2 when there's hardly any around, but if we add it at 30ppm, they need much less to do far more growth.

This biochemical machinery takes time to adapt to these concentrations.

Put another way, our bodies do the same thing.
If you where fed once a week say 14000 calories, vs 2000 calories per day, you'd adapt much better, be much happier with the daily rate.

Total would still be the same, but you'd be hurting near the end of the week.
I ran out of food on a long solo backpacking trip in the sierras, no food for 3 days (damn bears got my food). I adapted well after the second day, but it took time and I was not feeling too well. Needed salt mostly(which I had and rationed out).

It takes a week or two for plants to adapt, and in some cases, 4-8 weeks.
So changing things around is not good for them.
It confuses them basically, daily vs 2-3 times a week is okay, below 2x a week unless there is not much light etc, you ought to dose more often.

Now if you use mineralized soil or worm castings, or ADA AS, now you have a buffer, a source that is long term for all nutrients. So you can do a little of both using the sediment + water column, so then 2-3 week really does well, or even 1x a week if you have lower light. You can still do it daily and dose frequently etc, this will reduce the depletion of the sediment nutrients.

Tom Barr