It varies with how the tank has been running, what you have changed, and why.
High tech- you ought to see most changes in a few days to a week. Sometimes faster (ie: pearling when you adjust the CO2 can happen as soon as the CO2 has a chance to circulate in the tank)
Low tech, or slow growing plants in a high tech tank- changes might take a couple of weeks or longer to show up.
If the tank was close to deficient in something, and you add enough, you ought to see the change pretty fast. Better leaf color, faster or larger new growth.
If the tank was close to excess, and you add enough to be toxic you would probably see leaf spots pretty fast, but reduced growth or twisted growth would take a little longer to see. It happens right away, but the leaves have to grow out a bit for you to see.
If there was a good reserve of something in the substrate and you reduce the dosing, it may take time for the reserves to be used up, so the response to the deficiency will be delayed.
It should show up almost immediately.
Thank you for your response. I appreciate your thoughtful explanation.
I am not sure if I am High Tech or low light or what.
My tank was doing well then I crashed it. I have more time in my schedule now and am trying to recover what is still intact.
I recently revamped my dosing regimen, did 10% daily water changes to get my cycles of concentration down from the mid threes down to the low twos. The TDSppm on the city water is 223 and the tank is 678ppm. Now I am doing weekly water changes and using my new dosing regimen.
I recently put 2 or 3 Seachem root tabs in the gravel below the Amazon Swords to give them a shot in the roots.
My fish load is probably on the high side and in the past I did not have to dose Phosphorus due to test results above 1.0ppm and as high as 2.5ppm. Nitrite and ammonia have never been a problem with this tank.
My plants are Amazon Swords, Micro Sword, Pennywort and Ludwigia repens.
The Amazon Swords are pretty beat up and algae plagued.
Micro Sword is already making a comeback and has new growth with sister plants sprouting.
Pennywort and Ludwigia seem to be the strongest plants at this time.
This is my set up
46 gallon bow front
Net 57 gallons water (includes sump)
Natural gravel, rocks and Ironwood
Pro-flex Model 1 wet/dry sump filter with bio-media pack and seasoned EHEIM Substrat pro bio filter media. One 100 micron and one 200 micron bag filter.
Mag Drive supreme 950 gph pump on custom suction stand/header to keep pump motor above water level.
CPR CS-100 siphon overflow
AA Aquarium Green Killing Machine 9W Internal UV Sterilizer (night time schedule)
Coralife Lunar Aqualights Two Lamp Compact Fluorescent Strip Lights
Two 4-watt Lunar Blue-Moon-Glow LED lamps
One 96W Daylight 6,700*K (morning and evening hours)
One 96W Daylight 10,000*K (daytime hours)
Fixture +/- 22” from substrate
Glass hinged top on tank
Plastic lens on fixture
Fixture on factory stands
Coralife Aqualight Power Center Timer
8am – 8pm single light
12pm – 4pm both lights
8pm – 8am LEDs only
Excel 75mL /wk
Iron 23mL /wk
Phosphorus 7mL /wk
Nitrogen 14mL /wk
Trace 29mL /wk
Potassium 19mL /wk
5mL Prime with 10% weekly water change
Set point 7.0 maintained 6.95-7.05 pH
AquaticLife P/N 9000005 pH Controller
Matheson 81-2 Low pressure CO2 Regulator w/solenoid
10# CO2 cylinder
I have been doing my water testing every two weeks. My last water testing results (1/21) were:
pH 7.2 (degassed sample)
I do not test the calcium, it is always in the 180-200ppm range
With my degassed sample being 7.2 I cannot set the controller to 6.2 for the CO2 so I hit the excel harder on the dosing, 15mL every other day and double it after the water change.