Journal Greggz 120G Rainbow Fish Tank - Part Deux!

[Joel Armstrong]

I hope everyone who has joined is enjoying the forum.

Over time my plan is to post summaries of many of the discussions from my old long running thread that I kept on another site. Keep in mind these posts are my thoughts on a particular subject based my experience. Others may have other ideas which are just as valid. I am open to hearing other opinions and techniques and welcome any discussion these thoughts might generate.

To that end I will update this thread at times by cross posting my answers to questions asked on other threads. Today I responded to a post about remineralizing RO water. Here's a repost of my response.

I've been using RO for many years now.

The benefit of RO is that it has been stripped of pretty much everything, including dKH and dGH. So it's a blank canvas that you can remineralize any way you like.

Let's start with dGH which is commonly referred to as general hardness. It is comprised mainly of calcium (Ca) and Magnesium (Mg). It also includes things like iron and Manganese but these are normally in such small amounts it has very little affect on the calculation. If you would like to add back dGH, all that you need is CaSO4 and MgSO4. You can choose to raise it to any level you prefer, but most people that I know raise it to somewhere between 3 and 6 degrees.

You also can choose what ratio you would like between Ca and Mg. A general rule is about a 3:1 ratio of Ca to Mg. But some prefer 4:1 or 2:1. Personally I run mine at 2:1 for a total dGH of around 4.

Next you need to learn how to calculate how much you need to add to reach your target. You can use either the Rotalabutterfly or Zorfox planted tank calculator. Here's an example for my tank. In my 120G tank I have about 105G of actual water volume. If I want to raise my Ca to 15 ppm, here is the calculation. Note that the calculation also shows how much dGH is being added. You will need that number to calculate your total dGH.

Then you would do the same to calculate how much MgSO4 to add. Once you calculate that amount you add together the degress of dGH that each is providing to get your total dGH. Here how that looks in my tank.

This is the easiest and most cost effective way to raise general hardness. The other option is to purchase a commercial "GH Booster". These are normally comprised of Calcium (Ca), Magnesium (Mg), and Potassium (K) at a ratio of somewhere around 3:1:6. So two things you need to know about a GH booster. They add loads of K, and they cost many times more than the sum of the base ingredients. It's much more cost effective to buy your own CaSO4 and MgSO4, and you set your Ca:Mg ratio to anything you like.

Here is an example of a common commercially available GH Booster here in the US showing what it adds to raise dKH to 4 degrees.

Now on to dKH, which is referred to as carbonate hardness. Carbonate hardness is made up of either CO3 (carbonate) or HCO3 (Bicarbonate). Most people use either Potassium Carbonate (K2CO3) or Potassium Bicarbonate (KHCO3) to add dKH.

Before you get started you need to determine what level you want to raise dKH to. Personally I don’t add anything for carbonate hardness and run my tank at essentially zero dKH. Most plants prefer softer water and the softer the better. But if you choose to add carbonate hardness it’s easy to calculate. Here’s the calculation for my tank if I wanted to raise dKH to 2 degrees using K2CO3. Notice that the K2CO3 is also adding a large amount of Potassium (K). You need to keep this in mind as you calculate your other macro nutrient dosing.

One other consideration is how you dose both dGH and dKH. I dose mine into RO storage tanks. That way everything is premixed and dissolved when it gets pumped to the tank. I also dose all macro fertilizers into the storage tanks (NO3, PO4, K) as well, but that is a longer discussion.

You could also dose directly into the tank. But there are a couple of things to keep in mind. When raising dGH the Ca and Mg can take some time to dissolve, so you will have some time with white specs all over the tank. No big deal really as they go away in time.

When raising dKH, it’s always best to dose to a separate container and let it dissolve first. Even if it’s just in a small bucket. The reason is when you initially dose K2CO3 or KHCO3 there is a sudden large pH spike. It takes about 12 hours to come to come to equilibrium. I mention this is as depending on how much you are adding the sudden rise could affect livestock.

I hope that summary helps. If anyone has any questions I’d be glad to share my thoughts.

Hi Gregg,

If I'm correct, your previous dosing of Ca and Mg was Ca 25ppm to Mg 10ppm, was at a ratio of 2.5:1 ?

May I ask the reason for changing?

Cheers,
Joel

 

[GreggZ]

Hi Gregg,

If I'm correct, your previous dosing of Ca and Mg was Ca 25ppm to Mg 10ppm, was at a ratio of 2.5:1 ?

May I ask the reason for changing?

Cheers,
Joel

Good question Joel.

I frequently make small changes to my dosing just to see what happens. I recently lowered dGH just a bit and also raised NO3 a bit as well. I really don't think these small changes make that much difference. I am looking for shades of grey regarding plant health.

As to NO3 I am trying to test the theory that more NO3 causes algae. So far my first bump up has if anything made things just a slight bit better. And as to dGH my tank seems to do slightly better with a closer Ca:Mg ratio. For me 2:1 works quite well.

With many nutrients you need to think enough but not too much. So there is a range that can work well for most tanks. People sometimes get too caught up in nutrients which is only one piece of the puzzle.

FWIW here's all the latest.......

 

[Joel Armstrong]

Good question Joel.

I frequently make small changes to my dosing just to see what happens. I recently lowered dGH just a bit and also raised NO3 a bit as well. I really don't think these small changes make that much difference. I am looking for shades of grey regarding plant health.

As to NO3 I am trying to test the theory that more NO3 causes algae. So far my first bump up has if anything made things just a slight bit better. And as to dGH my tank seems to do slightly better with a closer Ca:Mg ratio. For me 2:1 works quite well.

With many nutrients you need to think enough but not too much. So there is a range that can work well for most tanks. People sometimes get too caught up in nutrients which is only one piece of the puzzle.

FWIW here's all the latest.......

View attachment 437

Thanks Gregg,

Appreciate your response and I value your feedback.

I'd also like to thank you for your recent help answering my questions and posting your 'tank charts', which has helped lead me to dry dosing and has given me a starting point. I'm only 3 weeks in, after previously using all in one.

I've read your comments previously that there is a range that plants like, and not to get too caught up on the exact numbers and ratios. That's helpful advice.

I've stuck my head a little further down that 'rabbit hole' you speak of, and I'm enjoying the learning curve.

Thanks again for taking the time to answer my questions.

 

[GreggZ]

I mentioned earlier that I am going to try to recreate some discussions from my old journal here. Today the topic is:

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.

 

[Ed Wiser]

Gregg have you ever did a ICP test on your tank water to see how it matches with what you think is actually in your water?

 

[GreggZ]

Gregg have you ever did a ICP test on your tank water to see how it matches with what you think is actually in your water?

Ed I have not gone to that level of detail......but I do like the idea. I may have to do that sometime just to see what it comes back with. But in general with my large water changes and use of RO water I wouldn't expect any big surprises as I control everything that goes in.

I don't test often these days but at times I have done pretty thorough testing of things like NO3, PO4, dGH, dKH , Fe, etc. I think I have a pretty good idea of what is going on in my tank, and it's actually pretty amazing how closely the readings match my expectations when I take them. At this point my regular testing is just TDS . If it got out of my usual range then I would know something is going on.

 

[Ed Wiser]

Always thinking about input/output what each plant actual uptakes. Think there are lots of guess but now hard data. Saltwater aquariums are using auto testing systems now. Knowing exactly.what is t
In the Aqurium every minute of the day.

 

[Art]

I've been speaking with the ICP test makers to see about freshwater testing. With all due respect to all of us, our hobby test kits (and us, the testers) are not very accurate.

The ICP makers told me they are happy to test but they don't have the data with which to compare and make conclusions like they do with saltwater. Perhaps we need to work with them to establish that baseline. I may have to talk to them about free testing for those with beautiful, stable and long-term tanks...

The difference with us and saltwater is that we normally don't require the precision that saltwater benefits from. Close enough is good enough for us because, as has been mentioned, plants will uptake what they need. The large water change then takes care of excess so accumulation isn't much of an issue.

I do think that ICP testing may be more interesting to @GreggZ and @Burr740 in the micronutrient world though. Testing for those is impossible on the hobby side while an ICP test can tell you how much nickel you have in your water.

 

[Ed Wiser]

Corals will suck up all the elements in the water fast if they are healthy.
Would be good to understand plants Health. Most plant discussion is anecdotal.

 

[GreggZ]

Corals will suck up all the elements in the water fast if they are healthy.
Would be good to understand plants Health. Most plant discussion is anecdotal.

Ed I agree most plant discussion is anecdotal. There is no one doing peer reviewed studies on planted tanks, and there are SO many variables that it's hard to draw any firm conclusions.

And I am not really sure if having that detailed information would have much impact. On the list of important things ferts are lower on the list. There are some generally accepted theories on uptake, but like you said it's mostly conjecture. In my tank I believe my plants uptake about 2 to 3 ppm NO3 daily. But that is just a guess based on years of measurements.

In the end if you get everything else right you have a lot of leeway with nutrients. If you don't have everything else right, then the best fertilizer combo in the world won't save you.

 

[Ed Wiser]

Plants can take a lot of abuse. They have developed in a world that is constantly changing. So they can put up with things not being exactly to their liking easier than corals. Who have developed in a never changing ocean. Each type of Cora has its place on the reef. A develop only when the condidtions where they settle is right.
Plants have a wider range of conditions.
Some have a narrower range than others.

 

[GreggZ]

So here's the next summation from my old journal.

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 level 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.

 

[Art]

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.

this!

 

[Ed Wiser]

Good work in figuring out what was needed.

 

[GreggZ]

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 @Burr740 .

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.

 

[Ed Wiser]

I think a lot of people just get lost with all the numbers. Why people use the one bottle of fertilizer model.

 

[GreggZ]

I think a lot of people just get lost with all the numbers. Why people use the one bottle of fertilizer model.

LOL yes no doubt that's true!!

This is an advanced lesson. Many start with a bottle of fertilizer, but as you grow in the hobby there are plenty of rabbit holes to go down.......and this is just one of many.

 

[Ed Wiser]

To me you right about front loading. Thou I would look at as matching the current nutrient level of the aquarium. Same as you want to maintain the proper KH level for a shrimp tank. A match your tds level. When doing saltwater tanks I actually mix my own salt mix. As I found down thru the years premixed sale varies too much from batch to batch. Keep a constant with a stem plants is more important that some other plant types.

 

[GreggZ]

I hope everyone is enjoying a wonderful Christmas!

A few days back I did a major reset of the substrate like I do every so often. I remove all of the plants and do a very thorough deep vacuuming. This time I also added a couple more bags of Landen soil.

The tank usually goes through a rough patch for a week or two after. Stirring up all that gunk and disturbing the beneficial bacteria wreaks a little havoc. The combination of the deep vac and the new soil can create a short term ammonia spike, which in turn upsets the balance of the tank and brings on some nuisance algae.

My strategy is to let things ride without uprooting things for a week or two. Let the new growth get going good then trim back all of the poor old algae infested growth.

I've been doing this for years and find the short term pain is worth the longer term benefit.

Here's where the tank is today still in the rough patch. I'll update as things progress. Hopefully things start to settle down and get back to normal shortly.

 

[Ed Wiser]

Do you do extra water changes during this time? How do the fish Handel the transition?.