Unexpected
Member
Always. Over on that other forum, you told me I might need to add a bit mid week when you first explained front loading to me. I actually didn't get my AGA submission because I messed up on this part. So definitely elaborate.
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GreggZ Planted Rainbow Tank!
- Thread starter GreggZ
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DeadFish
Member
Please do elaborate.
GreggZ
Member
Front Loading Macro Nutrients. What is it and why would anyone do it??
As some of you may know I have been front loading all macro nutrients right after a water change for years now. I get a lot of questions about that so I going to try and explain why this works for me, and why it may work for you.
When I got started I was dosing like the majority of people do. I’d perform a water change, have a day of rest (whatever that means?), then start dosing macros and micros on alternating days. I did this without really thinking much about it, it was just what I read and seemed like what everyone else was doing.
But along the way I began to notice something. Some plants seemed to really stall after a water change, and then would peak just before the next water change. This happened mostly to sensitive species or large fast growing colorful stems.
After observing this long enough I decided to rethink what I was doing. It occurred to me that with my large (70%) water changes I was removing a large amount of nutrients out of the water column. So I put together a spreadsheet to better understand and visualize what was happening in my tank. I also started thinking more about plant uptake of nutrients and tank generated nutrients. As I began to examine things more closely it really changed the way I looked at nutrient dosing.
Let’s look at my tank. At the time I was dosing 21 ppm NO3 weekly with 70% water change. For now I will ignore plant uptake and tank generated nutrients. Excluding any other variables this is what happens from one water change to the next. The number to focus on is the Daily NO3 in week 11. I used week 11 because as you may recall from the post on accumulation anything past week ten is reflecting the maximum theoretical accumulation.
It's not surprising you see a steep drop off of nutrients, and then a slow rise until they peak again just before the next water change. This also correlates exactly to what I was seeing with certain plant species. Their peak health was on the same timeline.
Now let’s say for the sake of argument that 30 ppm NO3 in the water column is the optimum number to keep the highest number of plants happy at one time. If that were true, why would I want my numbers to be constantly changing, and why wouldn’t I just want to keep it at that peak level?
One thing that I have learned over the years is that plants like stability. They don’t like change. I look at plants like a factory. After a period of time the factory is humming along. But when things change all of the sudden things are not so smooth. A good example is when you get plants shipped to you. Sometimes that plant will go through a pretty rough period. It’s adjusting to the parameters of your tank (CO2 levels, light levels, nutrient levels, etc.). But once it adjusts and figures things out the growth is robust and healthy again.
Since I am big believer in stability, I started looking at ways to keep my water column numbers more stable. So let’s say instead of dosing that 21 ppm NO3 in three doses, let’s dose all of it right after a water change. Well here’s how that looks.
Again pay attention to the daily NO3 level in week 11. Shocking, right? The water column level is completely stable. So which do you think is better for plants? For me there is no question it’s better to keep things as steady as possible.
Now those are very simple examples. I didn’t include plant uptake or tank generated nutrients. In my tank with my large fish load I have determined that the two pretty much cancel each other out (about 2 ppm per day each). But other tanks may be different. Let’s say someone has a high light tank full of stems but no fish so little to no tank generated nutrients. Let's estimate the plants are taking up 2 ppm of NO3 daily. How would that look?
As you see now the tank peaks with nutrients right after a water change then nutrients slowly get depleted throughout the week. In this case someone may want to split their dosing into two doses, ½ after a water change (replacing the nutrients), then two smaller doses later in the week. This is how that would look.
So you see in this case by splitting up the doses it keeps the water column more relatively stable.
My thought about posting this is to help people think outside the box, and not to be afraid to try something new. Every tank is different and you need to think in terms of what would work best in your own particular tank.
I can tell you this I have been front end loading macros for many years now and would never go back. If nothing else for the convenience factor. The interesting thing is that my readings are almost exactly the same no matter what day I take them, and my TDS is almost exactly the same right before and after a water change. I remember when I announced I was going to try this a lot of people gasped. Now I know a lot of people using the same or similar methodology. I hope that is interesting to some of you out there.
Unexpected
Member
Thanks for showing these. I think where I went wrong was front loading too lean. I thought the Landen Soil would cover the difference, but I lost the tank right before the AGA deadline.
The tank had other arrangement problems but it could have been a top 10 (I think). This is the only picture I have of it. I was pretty disgusted with my failure. I also had a few cutting issues with the colorata.
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GreggZ
Member
Yeah that pic has a lot of great Dutch elements. I think it would have scored well.
DeadFish
Member
Thanks so much, @GreggZ . Not to hijack your thread, but just to make sure I'm 100% clear, without testing (I refuse to because I don't care enough to at the moment) RBF calculator puts my NO3 accumulation at 21ppm by WC day. If I'm doing a 50% WC and removing 1/2 the NO3 (~11ppm,) I would just dose back the 11ppm then? This is very interesting to me as I also notice the same trends, particularly in fast growing stems. I know PAR changes as plants grow up, but I definitely notice a difference in plant color pre/post WC. Recently, I've been noticing that prior to a WC, R. Mini Butterfly will have a gorgeous pink (this is a slow grower for me) hue, and then immediately after, it loses color. However, it has only grown a few cm in that time and even without a trimming, it still will lose that color until it perks back up by the end of the week. Is this similar to what you've noticed? Based on your reply I will begin frontloading this week. I have a ton of fast growing stems and a fairly well stocked tank, so I'm operating under the assumption that accumulation from waste and plant uptake will cancel out as well.
Edit: I'm also operating under the assumption that these symptoms are non-CO2 related in my case as my pH controller drops 1.4 within 30 min and doesn't move for the duration of the PP.
Hi all,
When you've just added nutrients (and I'm also going to <"guess really nitrogen (N)">) the density of chlorophyll in the mesophyll chloroplasts is high enough to mask that pink colouring.
cheers Darrel
I'd guess it is probably to do with the chlorophyll density of the plants. The <"pink colours are the anthocyanin based pigments"> (in the cell vacuole) showing through the mesophyll cells.
When you've just added nutrients (and I'm also going to <"guess really nitrogen (N)">) the density of chlorophyll in the mesophyll chloroplasts is high enough to mask that pink colouring.
cheers Darrel
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DeadFish
Member
If I'm misunderstanding, let me know - However, I'm saying that at max nutrient accumulation prior to a WC is when I see the best color, and then a subsequent water change will decrease color for a day or two. I was not frontloading NPK, so accumulation would occur throughout the week. So if I'm understanding your post correctly, would that not have the opposite effect? I.e. reducing N w/ a WC bringing out more anthocyanin pigments?
GreggZ
Member
If your max accumulation is 21 ppm and you change 50% then you should dose the new incoming water to your max accumulation target. Let's say you remove 50 gallons, then the "new" 50 gallons is dosed to 21 ppm. To look at it another way all new incoming water is dosed to the targeted max accumulation.
This is what I refer to as "target" dosing. No matter how much water is removed, the new incoming water is always dosed to the target.
If you really want to geek out here is something I wrote up about this recently. This is the way I look at my tank and my dosing.
Target Dosing – What does it mean??
For some reason along the way the commonly accepted method of reporting dosing became posting the total ppm of nutrients you dose per week (NO3 : PO4 : K). As shown in the discussion above about accumulation depending on your water change schedule that can mean a lot of different things. So if you compare your dosing to others you may not be comparing apples to apples.
The odd thing to me is that common way we report dosing has little to do with the level of nutrients we would like to see in the water column. Which, if you think about it, is the whole point of dosing, right?
I prefer to look at my tank in terms of what I call “Target Dosing”.
So what does that mean? Instead of thinking in terms of how much you dose per week, instead start thinking in terms of the “Target” ppm you would like to see in the water column. This takes the water change volume and frequency out of the equation.
If we go back to the discussion on accumulation, you may remember that someone saying they dose 20 ppm of NO3 can mean a lot things. At 25% water change that means 80 ppm in the water column, at 50% water change that means 40 ppm in the water column, and at 75% water change that means 26.66 ppm in the water column.
So lets look at this another way. Let’s say my target is 30 ppm of NO3 in the water column. In my tank I change 70 gallons of water at a time. The way I calculate dosing is that I want to raise the “new” incoming 70 gallons of water to my “target” ppm. Here’s the calculation.
So why do I prefer to look at my dosing as dosing to a target? Well in my case sometimes I change my water once a week. Sometimes twice a week. Sometimes a full 70 gallons. Sometimes 35 gallons mid week. Makes no difference I keep it simple. If I remove 35 gallons I dose the new 35 gallons to my target. If I change 70 gallons I change the new 70 gallons to my target.
Here’s one more way to look at it. Below are my RO water storage tanks. It’s where I store the water that is pumped up to my tank during a water change. These tanks are constantly kept at the same nutrients levels. So all incoming water is pre dosed to my water column targets.
And there is one more advantage. Let’s say I am comparing my dosing to my friend Joe Harvey .
He might tell me he is dosing 28 ppm NO3. But his water change percentage is 90%.
And I might tell him I am dosing 22 ppm NO3. But my water change is 70%
And someone else tells me they are dosing 15 ppp NO3 with a 50% water change.
If we remember our calculation to find the maximum theoretical accumulation (ppm divided by water change percentage), it turns out we are all dosing to reach the same "target".
28 ppm NO3 divided by .90 = 31
22 ppm NO3 divided by .70 = 31
15 ppm NO3 divided by 0.50 = 30.
So to me this is a simpler way to think about dosing that makes it easy to understand what that dosing means. A few years ago I went on a crusade to change the way people report their dosing as their “target”….but it didn’t really catch on. Although I do see a few people here and there that I know now referring to it. So you might notice when I post my parameters I list the “target” ppm. I also convert that to the typical EI equivalent if I was performing the typical 50% water change that most do.
As usual I hope that helps a few people out there and offers another way to think about how you dose your tank.
GreggZ
Member
And as long as I am posting some of my nonsense here is something I wrote up about accumulation and why it matters.
Accumulation……what is it and why does it matter?
As you progress in the hobby, you will notice that people often report their weekly fertilizer dosing. You might see some report they are dosing NO3 : PO4 : K at 20:5:20.
First of all what does that mean? It’s the total weekly dose of each nutrient into the water column. People post it as a reference to their dosing schedule. In the above example someone is dosing 20 ppm of Nitrogen (NO3), 5 ppm of Phosphate (PO4), and 20 ppm of Potassium (K).
So most people think if I just copy this dosing then I am dosing the same thing. Makes sense, right? Well the truth is not really. The thing people don’t factor into the discussion is the water change percentage and frequency. Depending on those two variables that dosing can mean a lot of things, and if you aren’t on the same schedule then your water column nutrients could be wildly different.
To understand why you need to understand how accumulation works, and something we refer to as the maximum theoretical accumulation. The maximum theoretical accumulation is the highest level the water column ferts will accumulate to over a long period of time. It’s theoretical as we are not taking into account the uptake of nutrients by plants or the tank generated nutrients that come from fish waste, fish food, dead/decaying plant matter, etc. For what it’s worth in my tank I believe those two pretty much cancel each other out.
Let’s take a look at what happens when we dose 20 ppm of NO3 into the water column and perform 50% water changes once a week. The tank starts with 20 ppm NO3 in the water column. At the end of the week you perform a 50% water change which removes half of the NO3 which lowers the NO3 level to 10 ppm. Then you add another 20 ppm NO3 and the tank is now at 30 ppm NO3. And so it goes. The next week you remove 50% of the nutrients which brings the tank to 15 ppm NO3. Then you add another 20 ppm NO3 which brings the level to 35 ppm.
And this goes on and on until after 10 weeks you are constantly at your theoretical maximum. There is actually a formula to calculate this number quickly. It’s the ppm of the amount of nutrients dosed between water changes divided by the water change percentage. For instance in this case the theoretical maximum would be 20 ppm divided by 0.50 = 40 ppm. And note I said the amount of nutrients dosed BETWEEN water changes. If you are performing water changes every two weeks use the total nutrients dosed in those two weeks for your calculation. Same goes if you are changing water twice a week……..use the total nutrients dosed between water changes.
So why does this matter? First of all when someone reports their dosing it is not the same as reporting their preferred level of nutrients in the water column. It is simply reporting how much they are dosing. But let’s say instead of changing 50% of the water someone changes only 25%? What is the effect? Let’s use our formula. 20 ppm NO3 divided by 0.25 = 80 ppm. So you see the accumulated nutrients are twice as high. Then let’s compare that to someone who changes 75% of their water. 20 ppm divided by 0.75 = 26.66 ppm.
So the point is that if you think you are following someone’s dosing, if you aren’t performing the same water change percentage at the same frequency then your end result can be drastically different.
I put together the chart below to help visualize how accumulation works. If you can understand what is going on in this chart then you will understand accumulation and why it matters. Remember after ten weeks you have hit your maximum accumulation and the nutrient levels will be stable at the number.
I hope this is helpful to some folks. It’s something that should be discussed more often. I thought I would lay out my thoughts on the subject so I can refer people back to this when it comes up.
Accumulation……what is it and why does it matter?
As you progress in the hobby, you will notice that people often report their weekly fertilizer dosing. You might see some report they are dosing NO3 : PO4 : K at 20:5:20.
First of all what does that mean? It’s the total weekly dose of each nutrient into the water column. People post it as a reference to their dosing schedule. In the above example someone is dosing 20 ppm of Nitrogen (NO3), 5 ppm of Phosphate (PO4), and 20 ppm of Potassium (K).
So most people think if I just copy this dosing then I am dosing the same thing. Makes sense, right? Well the truth is not really. The thing people don’t factor into the discussion is the water change percentage and frequency. Depending on those two variables that dosing can mean a lot of things, and if you aren’t on the same schedule then your water column nutrients could be wildly different.
To understand why you need to understand how accumulation works, and something we refer to as the maximum theoretical accumulation. The maximum theoretical accumulation is the highest level the water column ferts will accumulate to over a long period of time. It’s theoretical as we are not taking into account the uptake of nutrients by plants or the tank generated nutrients that come from fish waste, fish food, dead/decaying plant matter, etc. For what it’s worth in my tank I believe those two pretty much cancel each other out.
Let’s take a look at what happens when we dose 20 ppm of NO3 into the water column and perform 50% water changes once a week. The tank starts with 20 ppm NO3 in the water column. At the end of the week you perform a 50% water change which removes half of the NO3 which lowers the NO3 level to 10 ppm. Then you add another 20 ppm NO3 and the tank is now at 30 ppm NO3. And so it goes. The next week you remove 50% of the nutrients which brings the tank to 15 ppm NO3. Then you add another 20 ppm NO3 which brings the level to 35 ppm.
And this goes on and on until after 10 weeks you are constantly at your theoretical maximum. There is actually a formula to calculate this number quickly. It’s the ppm of the amount of nutrients dosed between water changes divided by the water change percentage. For instance in this case the theoretical maximum would be 20 ppm divided by 0.50 = 40 ppm. And note I said the amount of nutrients dosed BETWEEN water changes. If you are performing water changes every two weeks use the total nutrients dosed in those two weeks for your calculation. Same goes if you are changing water twice a week……..use the total nutrients dosed between water changes.
So why does this matter? First of all when someone reports their dosing it is not the same as reporting their preferred level of nutrients in the water column. It is simply reporting how much they are dosing. But let’s say instead of changing 50% of the water someone changes only 25%? What is the effect? Let’s use our formula. 20 ppm NO3 divided by 0.25 = 80 ppm. So you see the accumulated nutrients are twice as high. Then let’s compare that to someone who changes 75% of their water. 20 ppm divided by 0.75 = 26.66 ppm.
So the point is that if you think you are following someone’s dosing, if you aren’t performing the same water change percentage at the same frequency then your end result can be drastically different.
I put together the chart below to help visualize how accumulation works. If you can understand what is going on in this chart then you will understand accumulation and why it matters. Remember after ten weeks you have hit your maximum accumulation and the nutrient levels will be stable at the number.
I hope this is helpful to some folks. It’s something that should be discussed more often. I thought I would lay out my thoughts on the subject so I can refer people back to this when it comes up.
MichaelJ
Member
Great writeup's @GreggZ !
Cheers,
Michael
I experience more or less the same thing in my tanks (low-techs). How do I know, you may ask? Well, a good indicator is that my TDS stays pretty much the same over time and in-between water changes (35% every 10-12 days)- within a 5-10 ppm margin. Very stable.
Cheers,
Michael
DeadFish
Member
Thank you so much for this. This is all appreciated. I guess my one question is that if we're assuming that fish waste / plant uptake cancel each other out, why dose the new water to the accumulation point if we already have half the accumulation remaining in the aquarium? If my target is 21ppm and I change 10g (50%,) why dose the new 10g to 21ppm when we have a residual ~10ppm in the tank? I really like this idea and can see the practical benefits, just curious if I'm understanding that correctly.
Edit: I should have looked at the flowchart a little closer. I get what you're saying about theoretical max accumulation now.
GreggZ
Member
As you probably figured out if you remove 10g of 21 ppm water, we replace with 10g of 21 ppm water.
DeadFish
Member
Yes, I confused concentrations. My bad.
Unexpected
Member
Hello Greggz,
Question, do you see any reduction in GH between water changes?
Question, do you see any reduction in GH between water changes?
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