To CO2 or not to CO2 ??

trd1

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Jan 14, 2008
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Hi, I have been running a non CO2 100g bowfront planted tank for the last 18 months

Weekly Dosing:
1.2 tsp KNO3
0.3 tsp KH2PO4
30mls Flourish
3 tsp Equilibrium
1 tsp epsom salts
1.5 tsp Aquasonic Carbonate Hardness Generator (raise KH from 10ppm to 30ppm)
I dose the main 100g tank first then I use 15g of this water to put in my other 2 smaller tanks (for their WC) & then refill the 100g tank with fresh water.

Fish load:
approx 110-mainly smaller fish ranging from Flying Foxes, tetras, halfbeaks, hatchet, guppies, cories, BN, + ghost & cherry shrimp. Filtration is an Eheim 2028 & circulation is a Koralia 2.

50% WC every 2 weeks (water is filtered through whole house sediment & carbon filtration) , 3x39W 3ft T5 HO on for 10 hrs (1100-1600hrs light are off). I gravel clean & trim etc once a month.

Most of the slow growers Anubias, Crypts, Java grow well. Ludwegia Repens grows fantastic for a few months then rots along the stems & branches, same with rotala macranda. Most of the other faster growers do well for a few months then rot away or the leaves grow smaller & paler etc.

Never had a problem with algae apart from some GSA on the rear glass. The last few months I have noticed for the first time some very small tufts of BBA on the Java fern which I manually remove, however it keeps coming back. This coincided with when I started to add KH generator, added new plants, fish load was getting close to current level & UV globe was past the 12 month stage. What could have triggered the BBA?

Finally convinced the big boss (she must have had a moment of weakness) to look at CO2. However, I don't really have more time to spend on the tank (we are expecting our 2nd child & renovating our home) so I guess I will use low light. Can I continue to use the current dosing/lighting regime while adding CO2 to get better looking plants or does it need to be modified?
 

Tom Barr

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Excel or Easy Carb might be a solution without going full on CO2 gas, but needs dosed daily etc.

You seem to be adding a lot of ferts for a non CO2, EI is geared for CO2/Excel type of Carbon enrichment methods.

Adding an SAE or two will also help.
Do not add KH stuff, leave it be.

SAE's will eat shrimp later as they grow however.
Also, check your PM's.


Regards,
Tom Barr
 

trd1

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Jan 14, 2008
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Thanks Tom

I have about 8 Siamese Flying Foxes (Crossocheilus Siamensis) & 8 ottos. All very well fed. Plenty of Ghost & Red Cherry Shrimp in there.

I was going on the single dosing amounts for a 100g CO2 tank, however only dosing x1 a week instead of the x3 for CO2. Remembering that included in that dosage are my 2 10g tanks as well (ie a total of 120g)

What non-CO2 dosing changes do you recommend? Any change in lighting?

Thanks
 

Tom Barr

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No light changes, just no water changes, less dosing, more reliance on fish waste.

See the non CO2 approach I have listed on the ARTICLE SECTION.

Should help a lot and reduce the labor.
Otherwise, consider the Excel routine which is not much more than you do now, and then you can have pretty much every species and a denser plant garden etc(if that's what you want without too much added labor)

Regards,
Tom Barr
 

VaughnH

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I don't think you have "low light". Three foot long T5HO lights will produce very close to high light at the substrate in a 20 inch high tank. And, up closer to the lights it wll certainly be high light. The floating, or at least near the surface plants are filtering the light a lot, which may be why you aren't getting a lot of algae with no CO2. I suspect the faster growing plants do fine as long as they are small enough not to need a lot of nutrients, but as soon as they get bigger, and are much closer to the light, they run out of carbon and "melt" so they can float downstream to better surroundings.

Pressurized CO2 does not add to your workload, except every few months when you have to go get a CO2 refill. I really think you would be very pleased if you went that way.
 

trd1

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Jan 14, 2008
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Melbourne, Australia
VaughnH;37398 said:
I don't think you have "low light". Three foot long T5HO lights will produce very close to high light at the substrate in a 20 inch high tank. And, up closer to the lights it wll certainly be high light. The floating, or at least near the surface plants are filtering the light a lot, which may be why you aren't getting a lot of algae with no CO2. I suspect the faster growing plants do fine as long as they are small enough not to need a lot of nutrients, but as soon as they get bigger, and are much closer to the light, they run out of carbon and "melt" so they can float downstream to better surroundings.

Pressurized CO2 does not add to your workload, except every few months when you have to go get a CO2 refill. I really think you would be very pleased if you went that way.
Hi Hoppy, thanks for the reply. I cut down from 4 T5's for 10 hrs a day (plus another 4xT5 for an extra 2 hours a day) to the current 3x T5 about 5 months ago. Everything seemed fine in comparison to some of the algae problems I've read about. Never saw any BBA (verysmall) until a few months ago.

I guess I either shut down a globe & run 2xT5 only or go the CO2 or Excel method. I am just a bit hesitant to take the next leap, because I don't want to create a large algae problem that I don't have at present due to my inexperience with CO2.
However on the other hand I would like to grow some other plants that I have had problems with. Essentially what I would like is to maintain my current dosing regime, low light & add either Excel or CO2.

Regards
Corrado
 

Tom Barr

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One thing to consider is that adding more luight, while not the horrid issues some might have, really is not the limiting factor for health and nice lush growth.

Healthy nice growth is much easier to care for than algae and 1/2 dead growth, plants that just sort of sit there and do not die.

The limitation in the tank is not light or nutrients, it's CO2.

Trimming the tank using CO2 is also not some chore, you can select species that grow slower and are easier to manage, hack things back, sell the cuttings to the LFS etc, on line locally etc.

I have tanks that I rarely trim, maybe once every 2-3 months.
But use CO2 + low light.

I'd not fear it as much as you might.
The Excel route will be fairly easy if you are already adding fish food daily.

If not, then the CO2 gas is likely a better route.

Regards,
Tom Barr