Black Brush Algae (BBA) and CO2

**Sleepy_lancs** · 23rd Aug 2006, 02:31

Hi All,

Re-tested the water. after 24 hours and 48 hours the parameters are the same.
Where Distilled water PH = 7.4
and Tank water at 8.0~8.1

How shall I conclude?

**Plantbrain** · 23rd Aug 2006, 15:13

Look at the table and see what the differences are.

So:

http://www.aquatic-plants.org/articl...hph_table.html

1.5 KH and 7.4 = 2.4 ppm of CO2.
3.5 KH = 2.4ppm also

But......the pH/KH says less than 1ppm.........so it should read if the alk was all bicarb: 7.6 a tad less.

So adjust your pH down 0.5 pH units or so fior real CO2 ppm's.

So the pH target you want is not 6.5, it's more like 6.0 or 6.1.
Make sure you have decent surface movement.

Regards,
Tom Barr

**Sleepy_lancs** · 23rd Aug 2006, 22:23

Hi Tom, I have trouble understanding in getting the 6.0. How should I read that? Care to explain further?

I know I need 6.0 but at 3.5? what happens if I do it at 4 KH?

Sorry I am slow in this type of stuff.

**PeterGwee** · 23rd Aug 2006, 23:34

Originally Posted by Sleepy_lancs

Hi Tom, I have trouble understanding in getting the 6.0. How should I read that? Care to explain further?

I know I need 6.0 but at 3.5? what happens if I do it at 4 KH?

Sorry I am slow in this type of stuff.

For your DI water + baking soda sample : KH=1.5, pH=7.4, CO2=1.8ppm
For your tank water sample: KH=3.5, pH=8.1 (but CO2 should be the same for both sample since they are exposed to the same amount of partial pressure.) Hence, pH = ~7.7 to get CO2 of 1.8ppm. pH= 8.1 (measured tank water sample pH) - 7.7 (actual pH) = 0.4 off....

In order to get around 33ppm of CO2, your measured pH should be 6.5-0.4 = 6.1.

Hope that help you to understand better.

Regards
Peter Gwee

**Sleepy_lancs** · 24th Aug 2006, 03:17

OOOO... Now I understand.. Okay. Thanks PeterGwee for taking your time to explain to me. Very much appreciated.

But I have a question. Wouldn't it mean that the livestock be subjected to a shock since PH will start from 8.1 and falls till 6.1 in 60 mins due to injection of CO2?

**PeterGwee** · 24th Aug 2006, 12:52

Originally Posted by Sleepy_lancs

OOOO... Now I understand.. Okay. Thanks PeterGwee for taking your time to explain to me. Very much appreciated.

But I have a question. Wouldn't it mean that the livestock be subjected to a shock since PH will start from 8.1 and falls till 6.1 in 60 mins due to injection of CO2?

Then you better don't do large water changes. Adding baking soda in large quantity is another issue though.

Regards
Peter Gwee

**Sleepy_lancs** · 24th Aug 2006, 14:37

Yeah.. I think I might go for water change once every 2 weeks. And have to mix the water outside the tank confirm it to be KH 4 before adding it into the system. 25% at most and I will aim for PH 6.2 and below. Any comment?

**PeterGwee** · 24th Aug 2006, 16:23

Originally Posted by Sleepy_lancs

Yeah.. I think I might go for water change once every 2 weeks. And have to mix the water outside the tank confirm it to be KH 4 before adding it into the system. 25% at most and I will aim for PH 6.2 and below. Any comment?

No, that is not the point. Large water changes causes the pH to swing up but the fish/critters are fine and love it which goes to show that it doesn't hurt. Adding baking soda causes osmotic shock due to changes in "salt" level which is completely different from CO2 gas changes in pH. (since no change in salt content.)

Regards
Peter Gwee

**Sleepy_lancs** · 24th Aug 2006, 17:04

Ahhh.. that maybe the cause of my jumping off the tank fish mystery. So how shall I overcome this? Use some other KH buffering solution?

**valice** · 24th Aug 2006, 17:28

I am reading this thread with much interest... Will be trying the methods here to figure out my actual CO2 ppm as with ADA soil, it is a PITA to find out the ppm...

But Sleepy_lancs, why you want to buffer your water in the first place with baking soda?

**valice** · 24th Aug 2006, 17:41

Originally Posted by PeterGwee

In order to get around 33ppm of CO2, your measured pH should be 6.5-0.4 = 6.1.

Hope that help you to understand better.

Regards
Peter Gwee

Peter, your pH value of 6.5 is based on kH to remain at 4dkH right? As there is a buffering effect in his tank?

**PeterGwee** · 24th Aug 2006, 18:14

Originally Posted by valice

Peter, your pH value of 6.5 is based on kH to remain at 4dkH right? As there is a buffering effect in his tank?

3.5dKH as given by Sleepy_lancs. The buffering effect is rule out by the comparison method with DI water + baking soda. That is the whole deal with the comparison.

Regards
Peter Gwee

**Sleepy_lancs** · 24th Aug 2006, 21:10

Isn't buffering the water would stop a drastic change for the livestock in the tank. I try to bring my tank to KH 4 for this sole purpose.

**Sleepy_lancs** · 5th Sep 2006, 23:03

Almost 2 weeks gone by, sad to report at PH 6.0 my BBA is growing well.. now turned into a lawn by its own right

. I'll still keep it going for another 2 weeks. If it doesn't stop, I'll have no choice but to again tear it down. Sigh.

**PeterGwee** · 5th Sep 2006, 23:13

Originally Posted by Sleepy_lancs

Almost 2 weeks gone by, sad to report at PH 6.0 my BBA is growing well.. now turned into a lawn by its own right

. I'll still keep it going for another 2 weeks. If it doesn't stop, I'll have no choice but to again tear it down. Sigh.

Sleepy, trim and remove all traces of BBA before it gets worst and add more CO2. I'll suggest you go get yourself a manifold with 2-3 needle valves. Use diffusers and locate them along the back of the tank (1 at each corner and 1 in the middle. For your filter return, use a spraybar and mount it vertically along one corner blowing along the backwall of the tank. (Place the inlet next beside it and make sure the outlet is blowing away from it. This ensures little mixing and good circulation.). You can add more powerheads to the tank to blast the CO2 mist around so that all parts of the tank gets it.

So, you use the pH/KH method to simple dial in and then add more slowly till the BBA stops growing or the critters/fish act weird. You need to make sure you have enough surface movement when you do this. (Slowly means example you are now adding 2bps and now you increase it to 2.1bps and not suddenly to 3bps!).

Regards
Peter Gwee

**Sleepy_lancs** · 6th Sep 2006, 00:47

Peter, I can't add more co2. Any more will result in death of my critters. The spray is definately enough. BBA is growing NEAR the CO2 enriched outlet rather than those away from the CO2 outlet. I can't remove all the traces of BBA unless I.. well.. kind of like peroxide everything... aii.. That means I have to tear it down again.

**PeterGwee** · 6th Sep 2006, 06:25

Originally Posted by Sleepy_lancs

Peter, I can't add more co2. Any more will result in death of my critters. The spray is definately enough. BBA is growing NEAR the CO2 enriched outlet rather than those away from the CO2 outlet. I can't remove all the traces of BBA unless I.. well.. kind of like peroxide everything... aii.. That means I have to tear it down again.

Do you have any surface movement?

Regards
Peter Gwee

**Sleepy_lancs** · 6th Sep 2006, 10:38

yes. Very much so. I tested it by putting some fish food. It gets swirl around (with or with my fans on).

**Plantbrain** · 6th Sep 2006, 11:04

Originally Posted by Sleepy_lancs

Almost 2 weeks gone by, sad to report at PH 6.0 my BBA is growing well.. now turned into a lawn by its own right

. I'll still keep it going for another 2 weeks. If it doesn't stop, I'll have no choice but to again tear it down. Sigh.

Something is not right then with the CO2 still.
Old growth might stay, generally if falls off etc.
NO3/PO4/Fe etc have no effect on BBA.
Light not much either.

So you really are left with adding gfood surface movement with the spray bar, a nice ripple is good, not a torrent. You can always add a bit more CO2, buyt this way the fish will have enough O2, since youer plants are not making any, because you don't have enough water movement/CO2.

This is a very old story, "I cannot add more CO2 because of my fish"
It's not so much the CO2, I have a ton and my fish are fine because I have good O2 from botht the water moevemtn and surface movement(night) and good plant growth during the day(O2 from plants).

I do not add CO2 at night, that's a bad idea if you like your fish.

High CO2+ high O2 is fine.
High CO2 + low O2 is bad.

That is why the fish are gasping.
And that is why you are scared to add enough CO2 to make the plants grow well.

Take care of the current, then try adding more CO2.
Otherwise you will

regards,
Tom Barr

**Sleepy_lancs** · 6th Sep 2006, 11:53

Well.. What can I say.. fishes are now swimming near the top daily with fishes leaping out of the tank. What would you do? Continue to bring the CO2 down? Okay lets try it. I'll continue to bring the PH down with CO2 and see what happens. Btw, what is the interval like? Add more CO2 and wait for 1 week and drop more or drop daily until I see BBA drops dead or turn white?

Forgot to mention that the new Java leaves seems to be BBA free.. Or perhaps just not yet infected. I'll monitor their progress.

PS: Its not a torrent on the surface but I can't say anything about under the surface. Should be fine.. the BBA on the leaves are well.. swaying.. lol

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