CO2 for a 450L tank

[alexyay]

I guess my first question is - is it just flourish excel that kills black brush algae or will a CO2 system work too?

Dad's got a 450L tank, so obviously (at a larger-than-recommended dose) he's going through flourish excel at a point where it's just a ridiculous cost - the BBA doesn't seem to be dying either

So, he's considering investing in a CO2 system - however we're both pretty clueless and have no idea where to start.

Can someone please list the things we would need (preferably "pre packaged" but it depends on the cost of that vs. DIY) for a low maintenance system for the 450L tank - he only has low light plants in there at the moment. Thank you :thup: the BBA is INSANE. It's just everywhere - he's got some SAEs but they're taking a while to do the job lol.

[SamH]

Firstly you need a CO2 cylinder, it should cost around $250-$300 depending on where you get it from. Then you need to regulate the CO2 coming from the cylinder with a regulator. Ideally your regulator would be dual gauge with a solenoid, anything less will be cheaper but a much harder to use. After that comes the check valve, bubble counter (optional) and diffuser. I prefer to get my gear overseas but others have had their cheap imported equipment fail.

[amtiskaw]

You'll need ferts, as well. Otherwise you'll just be swapping BBA for different algae - green dust, green spot, or the dreaded BGA.

I can't find the post, but I saved some info kiwiplymouth posted here last year.

All credit to kiwiplymouth for this - I found it really useful when I started out with high-tech and dosing ferts

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Postby kiwiplymouth » Sat Mar 10, 2012 8:55 am

I currently have 13 planted tanks, 5 of which are high tech, co2 injected and liquid fertilized based on Estimative index dosing.

Target ranges for optimal growth are:

CO2 range 25-35 ppm

Nitrate (NO3) range 10-30 ppm

Potassium (K+) range 10-30 ppm

Phosphate (PO4) range 1.0-2.0 ppm

Iron (Fe) 0.2-0.5ppm or higher

GH range 3-5 ppm or higher

CO2 range 20-30 ppm

NO3 range 5-30 ppm

K+ range 10-30 ppm

PO4 range 1.0-2.0 ppm

Fe 0.2-0.5ppm or higher

GH range 3-5 degrees ~ 50ppm or higher

KH range 3-5

You can order bulk dry ferts from Stocker. They usually run between $12-15 per kilo. http://www.hydroponics.co.nz/ You can order online but I recommend phoning them and asking for exactly what you want.

Order these:

Potassium Nitrate (KN03)

Monopotassium Phosphate (KH2P04)

To make a liquid macro fert solution that will achieve close to the above target ranges, add:

264g KNO3

57.6g KH2PO4

2L ordinary water

These will give you a complete macro nutrient solution of potassium, nitrate and phosphate in the correct ratios. The dose rate for the above solution is 1ml solution per 10L of tank water. Obviously, if you have only large tanks you can make a more concentrated solution so that the volume that you dose each day is less, but the amount of ferts will be the same. You can also add just the dry ferts.

So, every other day (or three times a week) do the following:

Macros (NPK)

Micros (trace minerals, etc.)

Iron

In addition, once a week do a 50% water change (this is essential for 'resetting' the system). After the water change, add a GH booster (e.g. magnesium sulfate/epsom salts) at a rate of 3/4 tsp per 200L of tank water. This provides essential magnesium and allows the plants to uptake nutrients.

I find some my tanks take more than the minimum dose of nitrates when the plant biomass increases. If you get green spot, increase the phosphate, if you get green dust, increase the nitrates and CO2, if you get BBA, increase the CO2. If you get hair algae, you have too much light for the CO2 and nutrients you are providing. It may take a week or more to fine tune as the plants start accelerating in growth.

The CO2 provides the carbon source but you can also use Excel and a liquid carbon source if your CO2 suddenly runs out.

Light is the limiting factor so in other words, when the lights are on, the plants grow optimally and the algae can't take over. If the lights are on too long, the plants will use up the nutrients and leave behind whatever they can't use - algae is not fussy about what nutrients they use so they can quickly take over in that environment. Aim for an 8 hour photoperiod. Turn the CO2 on one hour before the lights go on and turn it off one hour before the lights go off. You can also get a CO2 test, drop checker or something similar to ensure your CO2 levels are optimum. If the plants aren't pearling a lot, they might not be growing optimally.

All of this is based on Estimative Index dosing by Tom Barr. It is based on the theory that by providing unlimited nutrients (including carbon) the plants are not limited in growth.

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*) Unstable CO2-levels - BBA

*) Low NO3-levels and/or high PO4-levels - Cyanobacteria

*) Low NO3-levels - Dust algae

*) Low PO4-levels, very good climate overall - Green spot algae

*) High Fe-levels - Hair algae (Cladophora, Pithophora, Spirogyra, Audouinella?)

*) High Urea-levels - Staghorn or Green water

[camtang]

So the only ferts needed for EI doesing are Potassium Nitrate (KN03) and Monopotassium Phosphate (KH2P04)?

[alexyay]

What's BGA and dust algae? And we plan in dosing it with ferts, I just want the bba to go away lol. The SAEs are cleaning it up nicely, but that's not really a solution.

Do you recommend glass or plastic accessories?