Problem with HC and red plants

[jufesa]

Hi, I write from Colombia

I have a 36 liters aquiarium with follow specifications:

CO2 DIY 3 bps
Light: 1 T8 15w grolux
1 T8 15w dylight 6500K
2 bulb 15w 6500K

Fertilizer with Acualeaf ( micros), N= 15ppm P 1 ppm
Fishes: 6 tetra cardinal, 9 rodostumus, 4 guppy
10 hours photoperiod
PH: 6.6
KH: 4
GH: 10
TEMP: 27ºC

The problem is:

1- the rotala wallichi, limophila aromatica, and the ludwigia losses the red color, grow up fine but doesn´t have a red color.

2- The HC is green with bubles, but doesn´t grow i have 3 months and the same plant, i don´t have a carpet only parche

I have other plants, cryptocorines( nice bronze color), cabomba, java moss, riccia, higrophyla, microsorium pteropus, parvula (hair grass), this plants grow excelent, with bubles and vivid green.

 

[dutchy]

Hola, como estàs?

There are a few things that catch my attention.

Are you really using 60 Watts on 37 liters? That's a LOT, even with T8. The problem is that you also need a lot of CO2 to meet the CO2 demand of the plants. If they don't get what they need, various things can happen like discolouration of growth problems. Some plants will grow fast, but not because they are so healthy, but because they try to reach the surface, where conditions will be better for them (more CO2) I'm not sure that, for the amount of light you're using, your DIY CO2 can add enough. The way to go here would be a reduced amount of light, just using the T8's. Still 30 Watts on 37 liters. Less light means less CO2 demand, so the actual CO2 level in the water will be more equal to what the plants need. Do you know T8's should be replaced every two years?
The plants that you mention at 1. are very CO2 needy plants. The plants with lower needs, like crypts, seem to be fine.

If HC doesn't grow, mostly the problem is CO2 related.

A GH of 10 could be a problem for some plants, but if they were ok before, they should also be ok now.

Bubbles don't necessarily reflect plant health, it's more a consequence of O2 saturation and high light.

Other deficiencies might be a problem, I'd increase the N and P slightly, but also micros.

 

[jufesa]

Hola y gracias

Ok, if I low my light, rise the co2 levels and plants growth better (COLOR)?

I change my T8 every 10 months, and i have another question. High P level helps to red color in plants? how much?

And thanks so much Dutchy

 

[dutchy]

The important thing for now is that you get everything growing well. Then worry about colour and experiment with a little bit more light. A little bit at a time. There's a very delicate balance between light and CO2. Low light with high CO2 is very much ok, but high light with low CO2 = problems.

So whenever you use more light, you also have to increase CO2. If you can 't increase CO2, then more light is not possible. You might need a pressurized system.

It's also important that you keep the DIY CO2 working well, so replace before it gets empty.
I don't think its high P that really makes the plant colour, I think that with sufficient nutrients the plant finally can show its true potential. In the past people always had low P, because they thought it grew algae. So when more P was added, the plant showed better colour. That's not because of the P by itself, but a consequence of better plant health in general.

This is called "luxury uptake". The plant actually takes up more than it really needs and stores it.

Don.t rush things, take time to find the right balance between light and CO2, remember that plants can take around two weeks to adapt.