Need to understand how drop check works

[mbappaditya]

I have an 270L planted Tank, I have a pressurized CO2 system and a ISTA drop check,
As per the drop check, when the color of the liquid is green the CO2 is correct in the tank. I do 130 bpm and my drop check, turn to yellowish green
At night, when I switch off light, I switch off Co2 and start my aeration system; in the morning I find my drop check liquid as blue, which is very low of Co2.
I need to know,
Is it the correct process I am following?
How these drop checks works, can I relay on the result?
I have another question about fertilization when do I need to start fertilization and what kind of Fertilization should I use?

Thanks you in advance

[Joonkun]

a few things. you dont need to turn on aeration unless you have fauna. if you do then you still only need it if the co2 levels become toxic during the night. when not in photosynthesis plants produce co2. so unless it creates enough to kill you fauna then theres not really a need.

also, you fert when your water is not up to par for the minerals it needs. knowing what to fert and how often depends on the water composition. of course you could dose everything but its often a waste of money.
additionally unless you are a.) doing small water changes or ro water or b.) using EXTREMELY high light you dont really need to fert. large frequent water changes will replenish the minerals the plants have used. and plants can only use high amounts of minerals when under high light. more light = more photosythesis, more photosynthesis = more "food" the plant needs to sustain the process.

if you have really high light and not enough nutrition for the plants they will melt horribly.

so if your plants are gowing and look perky/pearling then you dont need ferts. unless your light is higher you dont need ferts. (you can use them but with out high light to force the plants to consume more resources its really a waste).

i've never really used a drop checker. truth be honest, the plants will tell you everything you need to know. looking for pearling, leaf perkyness, color ect.ect. will easily tell you if you are doing it right or not. co2 is only a small part of the process.

[mbappaditya]

I have around ~2WPG light, all plants in my aquarium is doing good other than the Red ones, Rotala rotundifolias are growing but leafs are not turning red, Cabomba red are also not doing well.. any cause !!!

I am using ADA Amazonia as substrate

[Joonkun]

at 2 wpg is really low if you want to have the reds of these plants. additionally dosing iron can help, but you need to upgrade your lighting to more like 4+wpg to get plants like that to get a really deep color. ferts are only part of it. i would wait and upgrade my lighting before i spend money to get a fert regiment down. i dont use co2 and only fert iron and flourish trace. and i get my plants to pearl. so i know you definately dont need to be high tech to get healthy plants. becareful if you upgrade lighting. some plants like crypts will actually melt in higher lighting.

[mbappaditya]

I have few Crypt too how about upgrading it to 3wpg... will it help

[Joonkun]

it depends on what you want to grow. to be honest unless you are trying to grow some of the more hard to care for plants. you dont really need a hi-tech tank. i dont really fert except some trace and not even that often maybe 1x a week. and i dont use co2 and im getting my moderate light plants to pearl.

[mbappaditya]

Thanks a lot for your input, much appreciated

[homemadepopcorn]

I have few Crypt too how about upgrading it to 3wpg... will it help

Watts per gallon is a very outdated way of judging whether or not you have enough light on your aquarium. Some specifications of your tank and your light will help judge whether or not you have sufficient light to grow the 'redder' plants.

[mbappaditya]

ok. My tank spec are as follows :

48"X18"X18", the substrates are ~20" away from light source.

I am using 36X4 OSRAM 6500K PLL - OSRAM DULUX L LUMILUX 36 W/865 2G11

[homemadepopcorn]

So it sounds like a standard 75 gallon? And by 36x4, I'm assuming you mean a 4 bulb fixture with 36 watts per bulb? Are these bulbs T5 or T8? Or perhaps something else?