Fertiliser advice...

[Karacticus]

Hi all.

It's been a little while since I last posted. I was hoping for some advice around spot dosing ferts.

I should start by saying that I am happy with my plant growth in the main. I clear a tray of plant material out most weeks and things seem to look nice and pearl readily (I know not the sign of pure health). I do still have a couple of anomalies that I would like to address:

My large anubias is looking more and more pale. It grows very near the surface, so I partly wondered if it is too much light as I appreciate it would be better suited to shade? Or would this likely to be a nitrogen deficiency? My frogbit is mid green currently and I'd like to get it closer to others I have seen on here.

I seem to be getting more GSA on the leaves of slower growing plants, like nana bonsai, which I know can be due to CO2 and flow issues. And I know is largely part of having an aquascape. It is in a fairly sheltered position, so probably in the least flowiest bit of the tank. I know additional phosphates can help.

Lastly, my Ricardia chamedryfolia has done nothing for months but stay dark green. Again, a phosphate issue? It is in good light and close to other thriving plants.

I am currently dosing APT 3 Complete at the recommended levels and am about to move to APT E at roughly half dosage. I have various dry salts, so was hoping someone might help me make up a 500ml mix for each of N, P, K and Iron please, or a combination that allows me to boost nitrogen etc when needed. I have tried several times to work the calculator, but I get lost every time. I would like to have a ready supply of ferts I can use to boost what is already going in from the AIO.

Info:

297l aquarium (minus hardscape etc)
23 degrees water temp
Chihiros WRGB2 Pro - 90% across RGBW.
7 hr photoperiod (including a 1hr ramp each end).
TDS: 235 (I have been converting to Spotless and rainwater to replace Bristol liquid rock water, so gradually getting it down)
pH 6.3
C02 injection via a reactor
Biomaster 850 and Nero wave maker which generates flow across the back.
50% water change weekly

I have access to: MgSO4, FeDTPA, KNO3, KH2PO4 and MnEDTA. Plus some Solufeed mixes.

I am playing around with the a few things to try and get the best outcomes, as I want to do a rescape and more classic design in the future. Maybe try something more challenging. Would be good if I can get fully on top of my game!

Thanks

Mark

 

[hypnogogia]

I can’t help, but tank is looking very lovely.

 

[Connswater]

additional phosphates can help

Personally I doubt it, your tank is magnificent, I think you just have the problem of mixing high light and low light plants, the low light plants in conditions optimal for high light, get some algae, they just grow too slow. The frogbit looks a bit Nitrate deficient but others might know better than me. Most floating plants seem to like a bit more Nitrate in the water column than rooted plants, perhaps >20 ppm. But I haven't put the latter theory to the test, but Nitrate is plentiful in my tanks and frogbit is darker green than your plants even under much more intense lighting, but honestly, really great tank, I would relax and bask in our admiration of your tank and maybe gradually remove the low light plants or put some more perpendicular hard scape in to deliberately shade them.

 

[Karacticus]

Okay, thanks. That is good to know. And thank you for the nice comments on my tank. I've found a simple recipe for KNO3 - well how much I need to add to make a basic solution - so will try that.

Have also found a thread about dry salts, which I need to spend some time absorbing.

 

[Zeus.]

so was hoping someone might help me make up a 500ml mix for each of N, P, K and Iron please, or a combination that allows me to boost nitrogen etc when needed.

Sure. NP
What solufeed mixes do you have and what dosing regime do you use from your 500ml mix

MnEDTA

Did you mean FeEDTA

 

[Karacticus]

Thanks @Zeus. I have 2:1:4 and Sodium Free TEC.

My plan is to keep using APT E (at half dose) daily with auto doser for my main AIO, so I was after a nitrogen supply to boost that where required - like if I had Flourish Nitrogen to address possible low N issues. Happy to use urea if better. Similarly, could I mix my own Flourish Iron, Flourish Phosphorus etc? Doesn't have to be a match to that brand, if that make sense?

I have FeDTPA and MnEDTA. I originally bought various ferts to make my own AIO - worked well in the main, but wanted to see if APT made any difference.

I would like to raise NO3 to maybe 20ppm to see what this does if anything. If I dosed 10ml daily of whatever you suggest? I can do whatever is easiest in terms of adding it.

Thanks again.

 

[dw1305]

Hi all,

I have 2:1:4 and Sodium Free TEC.

They should be fine, use the recipe in @Happi 's thread <"Solufeed 2:1:4 and Solufeed Sodium Free TEC or Solufeed Coir TEC Combination">. You can always dose a slightly higher volume (or does more frequently) to add more nutrients.

Similarly, could I mix my own Flourish Iron, Flourish Phosphorus etc? Doesn't have to be a match to that brand, if that make sense?

No, you don't have to match brands. They are all "ions" when in solution, so it doesn't matter which compound (or fertiliser mix) an ion has come from. The phosphate ion (PO4---) that comes from <"Flourish Phosphorus"> and is exactly the same as the PO4--- ion from <"Solufeed 2 : 1 : 4">. The only difference is price, and it is quite a difference.

Phosphorus supplement for the planted aquarium - A safe 4500 mg/L solution of potassium phosphate ...

Available Phosphate (P2O5)	0.3%
Soluble Potash (K2O)	0.2%

Flourish Nitrogen to address possible low N issues

<"Seachem - Flourish Nitrogen"> same issue again, a tiny amount of salts (ions) a lot of water and a very aspirational price.

​

Total Nitrogen (N)	1.5%
Soluble Potash (K2O)	2%

Amounts per 1 g​

Derived from: potassium nitrate, urea

You could also note that both Seachem products contain potassium (K) compounds. All do the calculation for "Flourish Nitrogen" and for the 100 ml container, this just means we can entirely work with ~100.

So "Flourish Nitrogen" is 1.5% N, and for potassium (K), 2 x 0.81 = 1.6% K, all potassium derived from potassium nitrate (KNO3).
Because we are mainly dealing with ("buying") water, we can say that 100 ml of solution weighs 100g, and we need the <"percentage potassium in KNO3">, for which we need the RMM = (39.1 + 14 + (3 * 16)) = 101.

I'm going to call that "100" and 39% K and 61% NO3, so 100 ml of "Flourish Nitrogen" contains 1 / 0.39 g = 2.6g of KNO3 and this also adds 2.6 * 0.63 1.64g of NO3 and 1.64 * 0.223 = 0.36g of nitrogen (N).

So we need another ~1.2 g of nitrogen from urea (CO(NH2)2) which is 46% N. Which means that we have 2.6 g of urea as well.

So ~£6.50 (approx. price of 100 ml of "Flourish Nitrogen") buys you 2.6g of KNO3 and 2.6g of urea so 5.2g of compounds (and a nice bottle, and some water).
The kilo equivalent, for the compounds, would be a mere:

192 (1000g / 5.2) x £6.50 = £1248. Nice work if you can get it.

cheers Darrel

 

[Happi]

I am currently dosing APT 3 Complete at the recommended levels and am about to move to APT E at roughly half dosage

Hello @Karacticus

I remember you were dosing this previously? or this? how and when you ended up dosing APT 3 ? maybe we can modify the Solufeed for your needs?

 

[Karacticus]

Hello @Karacticus

I remember you were dosing this previously? or this? how and when you ended up dosing APT 3 ? maybe we can modify the Solufeed for your needs?

Hi @Happi. Yes, I was using your mix and still grateful for your help with that. I can't fully recall how I ended up trying APT - I think it was from conversations with a well known aquascaping store. They use it and have amazing scapes - I changed a few things and was trying to gain some success with carpeting plants. And, the scientist in me decided to try a main brand to see if it had any noticeable difference. There seemed to be an improvement, but then I also increased my lighting and CO2. I completely understand the principle of nutrients mixed with water being sold at a premium, but I think my chimp brain took over and I bought some. I know shops want to sell their products.

@Connswater's comments make sense and I have suspected for a while that the anubias under high light is not ideal, as some of the anubias in shadier areas are deep green. My blyxa is growing beautifully and like a weed and my pinnafatida is doing well. There is a huge log of wood, which is amazing but creates some tricky spots.

I wonder actually whether I am just under-dosing the AIO leading to a few N issues. I know tests are limited, but nitrate is generally zero whenever I test.

I have also moved away from tap water, so am no longer adding high nitrates at source. I am instead adding a mix of rain and Spotless water. My plan was to get the TDS down to around 150, although I've been around 230 for a couple of weeks despite water changes.

If you're happy to look at a fresh mix for me, that would be great!

I was thinking of weekly cumulative dose:

NO3 - 20-30ppm
PO4 - 5-7ppm
K - 20-30ppm
Fe - 0.5-1ppm

When I can afford it, I am planning to rescape to a more classic nature style with full aquasoil and carpet (instead of capped with sand). And with that, look towards trying lean dosing.

And, thanks @dw1305/Darrel - you're always good at adding useful links and info!

 

[Zeus.]

Sorry was out yesterday



So did a clone of APT EI - did it at its recommended dose for dosing 20ml five times a week, if your after half the dose just dose 10ml etc.
Any tweaks just ask. We can also do a bespoke regime easy

 

[Karacticus]

Thanks, @Zeus. As an aside, if I dosed with dry salts, how accurate do I need to be? Can I round up to the nearest half gram? Just thinking would be a pain to weigh each time, but if I knew roughly I needed 1/4 tspn of Solufeed, then that might be easier than diluting with water into a bottle. Otherwise, I assume the above equates to two bottles - macros and micros?

 

[hypnogogia]

If you're happy to go with an EI type approach, then measuring in tspn is fine. Many of the original EI recipes used that as a measure for the dry salts.

 

[Zeus.]

how accurate do I need to be? Can I round up to the nearest half gram?

Well if we use teaspoons which are approx 5grams we get and add 6, 1, 6, 2 and 1 teaspoon of the relative salts we get -


Which isnt isnt bad IMO for a simple approach

 

[Karacticus]

Thanks @Zeus. So, in theory, I could do those teaspoon ratios once a week and be done?

Think I'll give the dry salts a go, although maybe split across three days or so. Or does that not matter? I've always assumed spreading ferts is better.

Perhaps once I've finished my APT.

 

[Zeus.]

So, in theory, I could do those teaspoon ratios once a week and be done?

In theory yes- adding them all at once after WC is a technique that folk use and is called front loading.
However, as Solufeed 2:1:4 contains Ureic nitrogen (7% N) which is a form of nitrogen that comes from urea, I would advise against front loading with it as it could cause a Nitrite spike which may be lethal to the inmates of the tank, esp with you dosing close to EI levels.
I would advise dosing 5 times a week with solufeed 2:1:4.
Dry dosing works , however weighing out 1.23grams of soluffed 2:1:4 and 0.22 grams of monopotassium phosphate etc is a little tricky every other day so making a stock solution makes sense. Dry dosing works easier when dealing with masses of 5grams+ IMO

 

[Karacticus]

Makes sense @Zeus., thank you!