Advice Please

steve todd

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after reading a lot of topics and posting some I’m still confused
Tank is 150g
Use pressurised CO2 using the CO2Chart I have Between 25-30ppm
Low light tank With only a few Anubias on driftwood
I was dosing the seachem flourish range of products phosphorus. Potassium and nitrogen and trace at their reccomended dosage.
What I would like to know is what is the dosage rate of NPK on this tank and how often
 

Phishless

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Tank is 150g
Between 25-30ppm
Low light tank With only a few Anubias on driftwood

What I would like to know is what is the dosage rate of NPK on this tank and how often

This is just my opinion on NPK for mentioned tank.
I would target the water column being a low-light tank.
20ppm of NO3 @ all times.
2ppm of PO4 @ all times.
Add a little K to get to at least 5ppm.
Test NO3 & PO4 occasionally (2 weeks) to see how it's holding up.
Low plant load so no need to lard it on all week long.
Test GH, don't forget about Ca and Mg?
Water change days may need to be a macro dosing day.

Hope this helps.
 

VaughnH

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What lighting are you using? I know you believe you have low light, but how low? Anubias require very low light, and grow very slowly, so you don't need much NPK to have enough for them. What substrate are you using?
 

steve todd

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Hopefully I can answer your reply. Don’t use substrate anubais r on driftwood they r the only plant I have as for light I’m only using 3 LED Tubes on 75CM deep tank this is how I thought it was low light

Cheers
Thanks for replying
 

Allwissend

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The thing with most Anubias is that even if all they need is available their growth rate is slow because of their metabolism. What @Phishless suggested is a good place to start. I would add that if fish are present you will probably have enough NO3 and maybe PO4 for the plants. The frequency of your dosing depends on how often you change the water. If I had a similar aquarium, with no/low fish stock, I will start with a wc every month followed by a full dose of NPK and micros every week.
That sounds like low light to me.
 

Allwissend

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Hi Steve, as the aquarium is focused on discus fish and there are only anubias, I would approach things differently. I think with the heavy feeding discus require, NO3 will be well covered so none is necessary or maybe 1 time dose of 5-10mg/L every week after water change is likely enough. If you use remineralized RO water, there will be enough Mg and Ca for the plants. If not add at least 3mg/L Mg per week. The rest dose as already described. If the plants show signs of problems increase dosing.

I would keep the CO2 going but not at 30mg/L, maybe 15 or 20mg/L. I think CO2 will create less problems than excel.
 

steve todd

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I’ve added too much nitrogen and now have 40 ppm after doing three 200l water changes the level has not gone down on my 670l tank is 40 ppm too high
 

VaughnH

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My tank shows about 40 ppm on my nitrate test every time I test it. So far, no fish problems. I'm pretty sure nitrate isn't a problem up to around 100 ppm.
 
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Allwissend

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Pretty much depends on the fish species and fish age. Some young fish may not grow as large if nitrate levels are very high. Thing is 40mg/L is not that high and then you have the random effect of the test kit. Nitrate test kits are notoriously bad when it comes to quantification.
 
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Allwissend

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Better to err on the side of caution here. Let's say the worst case scenario is your K levels will be under 5mg/L. So the target is to have 5 or above.

Best way available for us to be sure there are 5 or above mg/L K in the water is to add 5 or more mg/L K to the water. For example 10mg/L KNO3 will add 6.1mg/L NO3 and 3.9mg/L K.

Then the question is "how often ?". The answer is mostly influenced by water changes and plant uptake rate. From others with higher light aquariums, we can say that the demand for K should not be larger than 20-30mg/L per week. So adding 10mg/L K per week should be enough for the aquarium setup you describe.

PS. The same rationale can be applied to all other fertilizers and skip test kits altogether.
 

VaughnH

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Better to err on the side of caution here. Let's say the worst case scenario is your K levels will be under 5mg/L. So the target is to have 5 or above.

Best way available for us to be sure there are 5 or above mg/L K in the water is to add 5 or more mg/L K to the water. For example 10mg/L KNO3 will add 6.1mg/L NO3 and 3.9mg/L K.

Then the question is "how often ?". The answer is mostly influenced by water changes and plant uptake rate. From others with higher light aquariums, we can say that the demand for K should not be larger than 20-30mg/L per week. So adding 10mg/L K per week should be enough for the aquarium setup you describe.

PS. The same rationale can be applied to all other fertilizers and skip test kits altogether.
And, that is why the EI dosing method works so well. We are fortunate that the level of nutrients that is harmful is so much higher than the levels we dose at, even with the EI method. If the "too much" levels were much lower than they are the EI method wouldn't work at all.