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161 Posts
Discussion Starter · #1 ·
Here's my situation, I am starting a new tank and would like to maximize growth so that the tank can fill-in quickly. The problem that I'm having is that whenever I follow EI, I get massive GDA breakout. Plant would growth well for the first few days after water change but then goes down hill. GDA would take over and my plant would start to stunt, especially on fast growing stem plants. When I reduce nitrate to below 5ppm and reduce my light output, GDA decrease but so do growth. So, that is my dilemma.

All of my other parameters are good and I have pressurized CO2 with 30ppm. I'm using Coralife Aqualight Pro, so I can easily adjust my light output from 2wpg to 5wpg. It uses 2 150watt MH and 2 6700K power compact. GH is raised to 4 degree with Equilibrium. KH is below 1ppm. PH is around 7.2 without Co2 injection and 5.9 with Co2 injection. Phosphate is at 2ppm from the tap. Since it's a start up tank, it's very lightly stocked with 10 SAEs, 10 Otos, 10 Amanos, and 6 Black Mollies. The tank is lightly planted, filling about 1/5 of total tank space. Those are my parameters.

So how do I maximize growth during this early start up stage? I've spent a lot of money on my lights and It's a shame that I have to dial it back in order to prevent algae. I'm willing to do water changes every day and up my nutrients and my light. Would this help?

Thank you in advance for any advice you can provide. I've been in the hobby for many years and I always find tank start up situtation very difficult, partly due to my lack of patience and my need of immediate gratification.

161 Posts
Discussion Starter · #3 ·
I like to challenge myself - that's the whole reason I got the Aqualight Pro. If I keep it simple, I would be going backward and reverting back to PMDD.

13,609 Posts
Do the DSM method.

Algae grows because there are not enough plant biomass to start with.
Daily water changes, particularly if you do them in the monring, say 1-2 hours after the lights come on, is a great way.

GDA is typically always a CO2 issue to induce it.
I've tried a dozen things or more on 3 tanks to inoculate GDA, never been able to do it unless I messed with the CO2 as well.

Once established, the cycle takes a few weeks to get rid of.
If the CO2 is good to start with, then there's little issue. New tanks have lots of trouble dialing in the right CO2, they also have folks who spend 600$ on a high powdered light, but not enough adding enough plant biomass from the start:redface:

More plants= less algae.

DSM gets around that issue, established a very effective root matrix, cycles all the bacteria, no CO2 limitation, no labor/water changes etc.

A few weeks later, you fill and flush 2-3x and off you go.

Folks seem to love to blame in this and many other hobbies.
Nutrients are the perennial favorite for algae.

And yet when the system is stable and you use a reference, they are quie independent of algae. If you do not use a stable reference, then there's always some unknown dependency and you cannot reach and logic based conclusion about your question about nutrients. Many seem to like to try however, and that's where they get into trouble/s.

If you have lower light intensity, since you bring up PMDD, Paul and Kevin used very very low light, about 1/2 the light your fixture uses at 2w/gal. I know this because I have a aqua pro light and a PAR light meter. I also have some old data from the tanks Paul and Kevin used.

Less light= less CO2 demand(therefor, management/dialing in a good stable CO2 is easier)= less nutrient demand.

This is not about limiting algae, it never was.
I have no clue why so many other methods and folks seem to think this when it cannot be true.

It's about providing good conditions for aquatic plant growth.
Light/CO2/nutrients, that's all.

Add lots of plants from the start etc, cycle filters, get things grown in well prior, take more care to do water changes, watch the tank, the plants and adjust CO2 etc.

It has nothing to do with fiddling with a few ppm's here or there with some nutrients.

Mistergreen gave you good advice.

Asking for a challenge vs trouble is not too far off.
Once things are grown in, CO2 good, routine water changes, care, etc then start trying higher light. More is not better, this is more true with light than any other parameter.

Light is the most stable of the 3 main parameters, so it makes the best solution to adjustments of growth rates, algae management, using less of the CO2/nutrients.

When you add more light, you need correspondingly more CO2, which leads to more nutrient uptake and so forth. Reducing light does the opposite.

Less CO2/nutrient demand.

It's pretty simple.

But many want high light and little work.

Tom Barr
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