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Is this GDA?

K

Kam Sandhu

Member
Joined
11 Aug 2014
Messages
112
Hi all,

Just wanted to know if this was GDA in my tank?

I've had it for 2 weeks now and just been letting it live out its life cycle before wiping it off.

Is that the best course of action?

GDA1.jpg


GDA2.jpg
 
Duration isn't the problem, intensity (PAR) is what causes the Algae. Not enough CO2 and poor flow are other factors, but in the case of GDA I don't believe these contribute.

You need to find a way to dim your lights. It's easy to get trapped in the mind set that "the more light the better", but this is not the case.
 
Julian said:
Duration isn't the problem, intensity (PAR) is what causes the Algae. Not enough CO2 and poor flow are other factors, but in the case of GDA I don't believe these contribute.

You need to find a way to dim your lights. It's easy to get trapped in the mind set that "the more light the better", but this is not the case.
Click to expand...

Hmmmmmm I have 2xT5 45 watts each plus reflectors.

I think my co2 plus distribution is OK. Diffuser on the right and drop checker on the left, green on lights on.

I was under the impression GDA is expected on new setups and should last about 3 weeks? I was waiting until the 3rd week before cleaning it off.
 
Sounds like a good plan but I've done the whole "wait for 3 weeks" thing and it just came right back again. I agree it's not completely avoidable in a new set up but your case looks a bit more severe which is why I suggest lowering the intensity.

You have nothing to lose by trying.
 
Julian said:
Sounds like a good plan but I've done the whole "wait for 3 weeks" thing and it just came right back again. I agree it's not completely avoidable in a new set up but your case looks a bit more severe which is why I suggest lowering the intensity.

You have nothing to lose by trying.
Click to expand...

Yeah that's the plan. Maybe even do a black out and if that fails remove reflectors.
 
Clive,

Thank you for the links, I did find those as I was reading up on GDA.

So, this raises a few questions...

I (as most people) assume I have good CO2 distribution. I keep my drop checker on the opposite side to my diffuser and it is always a nice green when lights go on, I see tiny CO2 bubbles all over my tank, right to the furthest corners. All plants are growing well and spreading. So how do you tell if there really is a CO2 problem?

Lights wise, this can be reduced by removing the reflectors, but honestly, I have only had GDA for a couple of weeks and want to let it run its life cycle before doing a 3 day blackout followed by wiping it away and doing a big water change. One of the reasons is, I do not have many fast growing plants, I have loads of Eleocharis sp mini and some java moss. So algae would be expected?

Am I doing the right thing in waiting? I am not in a rush to get things cleaned, but rather correct the issues.
 
Id remove the reflectors and only use a songle light until it clears.
Reduce the light and remove it and see if the algae stops.
I had a small problem with high light that I thought was quite low and turning off one of the units fixed my problem :)
 
mr. luke said:
Id remove the reflectors and only use a songle light until it clears.
Reduce the light and remove it and see if the algae stops.
I had a small problem with high light that I thought was quite low and turning off one of the units fixed my problem :)
Click to expand...

Removing reflectors are not a problem, unfortunately its not possible to run a single light on a Juwel hood.
 
mr. luke said:
Why dont you turn one over and attach it to the underside of one of the tubes?
Click to expand...
That's what I did when I started my tank. I was using 2 x 25W T8's over 180litres. After a month or so rotated the reflectors round to increase light levels. Saw no algae.

You have 90Watts of light and unless your tanks if over 350litres (90US gals) & therefore less than 1Watt/gallon and unless you are careful, you will get algae issues with that level of light.
 
Kam Sandhu said:
I (as most people) assume I have good CO2 distribution. I keep my drop checker on the opposite side to my diffuser and it is always a nice green when lights go on, I see tiny CO2 bubbles all over my tank, right to the furthest corners. All plants are growing well and spreading. So how do you tell if there really is a CO2 problem?
Click to expand...
Because you have GDA mate. It's that simple. People love to buy test kits to supposedly tell them what their water parameters are, but the best test kit in the world are your plants and algae.
So when you see the first signs of GDA, or any algae for that matter, immediately, the first reaction should be to cut your light intensity by at least 50% because light is at the top of the food chain. It drives everything. Your CO2 and distribution might have been fine for lower light intensities, but not for the intensity you have now. So if you want to keep using that light intensity then you have to have amazing CO2/flow/distribution. Since it's very difficult for people to be amazing then the easiest path is to start your tank with much lower intensity than you have now. Julian touched on this in his post #4. We are programmed by The Matrix to add as much light as possible, but this is the wrong path.

Again, watching bubbles is a pointless endeavor. You need to look at the pH profile in order to determine how the CO2 is behaving as well as to reduce the light.


Kam Sandhu said:
So algae would be expected?
Click to expand...
Again, I don't know where that is written, somewhere in The Matrix no doubt. I don't get algae and I don't expect it. You should only expect algae if you are doing something wrong.

Cheers,
 
This is why I love this forum. Fantastic advice.

As soon as I get home I will remove one reflector and turn the other upside down, run on one light and see how things go.

Is it best to leave CO2 at the current rate? Or can I reduce it due to less lighting?
 
Well Again, one can never have too much CO2 as far as plants are concerned. This only becomes an issue if fauna are involved. So if there are no fauna then I would turn the CO2 up as much as I could afford to buy CO2.

As I mentioned, sometimes it's not the amount of CO2 being injected that is problematic, but the timing of the CO2. The water needs to have max saturation when the lights first come on. If that doesn't happen then the plants can suffer which will trigger an algal bloom. So even if you have high CO2 later in the day, the damage would have been don at the beginning of the photoperiod and then it's too late to have high CO2. That's why you should do a pH profile check.

Also we have no idea about your distribution technique. We cannot see how it is accomplished based on your earlier photo. If you could show us how the filter outlet(s) and any auxiliary pumps/powerheads are arranged we could have a better analysis.

Cheers,
 
Cool, I will leave CO2 level as it is.

Currently CO2 comes on 1.5 hours before lights, drop checker is green but not lime green. So today I have increased that to 2 hours.

Lights on for 4.5 hours, CO2 off 1 hour before lights off and the drop checker is a very lime green.

Here are pics of my filter and powerhead. Albeit, photos are not great.

GDA3.jpg

GDA4.jpg

GDA5.jpg


So the lily pipe is pointing towards the front glass and up to ripple the surface, the powerhead is above the CO2 diffuser pointing right to left.
 
Kam Sandhu said:
So the lily pipe is pointing towards the front glass and up to ripple the surface, the powerhead is above the CO2 diffuser pointing right to left.
Click to expand...
(I see no lily pipe ?). This setup will immediately have CO2 distribution problems, especially in area below the powerhead, all the rear wall and in my experience in the opposite diagonal corner. This will get worse as plants grow and block the poor flow you have. This poor distribution and flow and too much light explains your issues. I assume that is algae on back of tank as well, reinforcing my observation of poor rear flow.

Using the my Juwel internal 600l/hr filter, even attempting to make my own spray bar, I got nothing like the flow and distribution I get now with a decent external filter and spray bar.
 
ian_m said:
(I see no lily pipe ?). This setup will immediately have CO2 distribution problems, especially in area below the powerhead, all the rear wall and in my experience in the opposite diagonal corner. This will get worse as plants grow and block the poor flow you have. This poor distribution and flow and too much light explains your issues. I assume that is algae on back of tank as well, reinforcing my observation of poor rear flow.

Using the my Juwel internal 600l/hr filter, even attempting to make my own spray bar, I got nothing like the flow and distribution I get now with a decent external filter and spray bar.
Click to expand...

Maybe lily pipe isn't the correct term. I meant filter outlet.

And yes that is algae across the back. That's where the most is.

Unfortunately, at the moment, an external filter is now an option.

I don't mind moving outlets, powerhead etc. Any suggestions?
 
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