# GDA on back wall of tank



## Tebo (14 Oct 2012)

Hi all,

I seem to have a lot of gda growing on the back wall of my tank.

Some tank details
200 litre
Fluval 306
Spray bar pushing back to front across the top of water, causing flow but not really breaking the surface
Aquagro 1000nd x3 lights 
CO2 lime green

Tank has been running around 10 weeks now.

I have tried light brightness up/down, extra ferts.  The only thing I feel is left is that there isn't adequate flow around the tank from front to back.  

Any have any thoughts around this ?

Should I get a better external filter, as I know the 306 isn't great output.  Or try a power head unit ? If so any recommendations.

Let me know if I have missed any other useful info?

Look forward to ideas on what to try next.


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## ceg4048 (14 Oct 2012)

Check the following GDA threads:
viewtopic.php?f=19&t=13207
viewtopic.php?f=19&t=17859
viewtopic.php?f=19&t=7031

Cheers,


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## Tebo (14 Oct 2012)

Thanks for the links, if I am reading the details correctly, lowering light intensity or a few days blackout. Is the way to go?


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## ceg4048 (15 Oct 2012)

Hi,
   Well I would certainly begin with a 3 day blackout. Then, afterwards, I would keep the lighting very very low and keep the CO2 very very high unless there are fish in the tank. It's entirely possible that under your current lighting conditions, the Fluval 306 was simply not man enough for the job. A 200L tank ideally requires 2000LPH of flow rating. I checked some websites to get an idea of the throughput ratings and I saw values ranging from 1000LPH to 1125LPH. You need to totally ignore the data  indicating "Recommended for tank Size" because that data is irrelevant for planted tanks which employ Darth Vader planet killer levels of photonic radiation, such as what you are using.

Anyway, it looks like you need to buy a second Fluval 306 to meet that throughput requirement, or you'll need the dropchecker in be far in the yellow to ensure proper flow/distribution. Until then, you'll need to keep the lighting intensity extra low.

Cheers,


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## Tebo (15 Oct 2012)

Thanks for the feedback, will start that process today when I get home.

On the external filter side, do a lot of people run two externals ? as I don't see many filters with high lph throughput advertised ? the best I can find is the Fluval FX5 External Filter, unless I am looking in the wrong places.


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## ceg4048 (15 Oct 2012)

Yes there are lots of people running multiple filters or large powerful filters. The FX5 has great flow, but the problem is that it achieves that flow rating using a large diameter hose and that no one else uses, so attachments such as external heaters, external CO2 diffusers and so forth are not easily made compatible. Eheim do higher rated filters such as their Pro 3 series, but these are very expensive. That's why I suggested a second 306. If you can afford these other options then I would highly recommend them.

Cheers,


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## Tebo (16 Oct 2012)

Thanks for the reply.

Would it be a bad thing to reduce the pipework from 25mm ? down to 22/17 on the FX5 ?  I am assuming these reducers are available, my limited plumbing knowledge would make me think this would increase the water pressure coming out of the spray bar ?  Reason I ask this is I have an external inline heater and also an inline CO2 diffuser that I would prefer to keep out of the tank if possible.

The Eheim externals do seem quite high prices compared to the Fluval, the flow rates also don't seem to be relative to the price between both manufacturers.  I am guessing the Eheim lph figures are more accurate and trustworthy rates for the units perhaps ?  therefore not a like for like comparison.  But the FX5 does seem to be more my price range. A second unit is also an option, just trying to workout the best way forward here.

I started the 3 day blackout,  I assume a blackout really is that, and I should cover the tank to remove any artificial light also, not that there is a lot where it is situated.  As that is what I have done at this point.

Also would my fertiliser have any impact on algae ? the one I was sold by the lfs was JBL Ferropol, but it seems reading on this site that an EI mix is a better route, and I see one of our site sponsors have starter kits for sale for this, would this be a more preferred method of adding fertilisers ?

Also what media is recommended within the filter? would this have any impact on the algae ? currently there is a coarse foam, ceramic tubes and carbon in the three layers(default items that came in the filter kit).  But again the more I read it seems Carbon isn't great when adding fertilisers, should this be removed, what should go in its place ?

The problem I have right now, there is too much information on this site and its difficult to know the right direction to move forward with it as to what is relevant to my situation.


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## nry (16 Oct 2012)

I have the same 'issue' however my oto's love the stuff so I tend to leave it there mostly   If I ever scrape it off, I'll most likely do this whilst siphoning away the scraped material to reduce how much spreads into the water column.


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## Tebo (16 Oct 2012)

I am hoping to get some discus for the tank, when I am happy it's stable and ready for them.

Thanks


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## ceg4048 (17 Oct 2012)

Tebo said:
			
		

> Would it be a bad thing to reduce the pipework from 25mm ? down to 22/17 on the FX5 ?


Yes, it would be an extremely bad thing. It would be so bad that it would completely defeat the purpose of buying an FX5 in the first place.



			
				Tebo said:
			
		

> I am assuming these reducers are available, my limited plumbing knowledge would make me think this would increase the water pressure coming out of the spray bar ?  Reason I ask this is I have an external inline heater and also an inline CO2 diffuser that I would prefer to keep out of the tank if possible.


Try not to think that. Think instead of the extreme case, if for example, you were to reduce the diameter to zero. What would happen to the downstream pressure? Yes, the pressure would reduce to zero and the downstream flow would also reduce to zero. Therefore, as you approach a zero diameter you also approach a zero flow. Using a reducer on an FX5 will choke and suffocate the very same flow you would have spent your hard earned money to get. In general flow dynamics the smaller the cross sectional area the lower the pressure, the lower the flow and the higher the velocity. People see a higher velocity being squeezed out of a small restriction and they assume that this means a higher flow rate. But we are not interested necessarily in increasing the velocity of a small amount of water, we are interested in moving large masses of the fluid and that is best achieved by having as wide an area as possible, to allow more kilograms of fluid to move across a given point per second, even if the velocity of those kilograms is lower.



			
				Tebo said:
			
		

> The Eheim externals do seem quite high prices compared to the Fluval, the flow rates also don't seem to be relative to the price between both manufacturers.  I am guessing the Eheim lph figures are more accurate and trustworthy rates for the units perhaps ?  therefore not a like for like comparison.  But the FX5 does seem to be more my price range. A second unit is also an option, just trying to workout the best way forward here.


No manufacturers claims of flow rate are accurate. That's because they measure and report the flow rate with almost zero head pressure and with no filter media inside the canister. The resulting numbers are always inflated, but our 10X rule is based on the manufacturer's rating because they all perform the same measurement trick, so that each unit can be compared directly. Our 10X rule takes into account the illusion of the filter ratings game.

In any case this is why I suggest that it would be better to use a second filter since you already have one filter in place. You would simply use a spraybar for each and the spraybar is already sized for the filter outputs. Then you combine the two spraybars across the back wall along the length of the tank. You can also feed gas directly into each of the two filter input tube grilles so that each filter will process CO2 into each of their respective spraybars. This gives even distribution of flow as well as even CO2 saturation across the tank. It is a more complicated setup but might be better value overall. If you decide to go with an FX5 then you should avoid reducers and fashion your own spraybar using plastic PVC tubing that fits the hose size.



			
				Tebo said:
			
		

> I started the 3 day blackout,  I assume a blackout really is that, and I should cover the tank to remove any artificial light also, not that there is a lot where it is situated.  As that is what I have done at this point.


Yes, Blackout means black. No light, no peeking, no feeding, no ambient light, no CO2. As black as black can be. Light triggers algae, therefore absence of light is the bane of algae.



			
				Tebo said:
			
		

> Also would my fertiliser have any impact on algae ? the one I was sold by the lfs was JBL Ferropol, but it seems reading on this site that an EI mix is a better route, and I see one of our site sponsors have starter kits for sale for this, would this be a more preferred method of adding fertilisers ?


Algae do not really care about fertilizers. They care about light. This is the reason people get into trouble in the first place, because they assume that nutrients cause algae so they don't feed the plants, they don't think about CO2 or flow and they use high light. So the result is that the plants starve to death and algae love it. If algae want to feast on fertilizer all they have to do is to feed on the rotting remains of the starving plants. I strongly suggest that you get the EI starter pack and that you stop listening to your LFS when it comes to the subject of plants. LFS may know about fish, puppies or frogs, but they typically don't know anything about plants. The EI starter pack will cost you 100X less than Ferropol. and will be 100X more effective.



			
				Tebo said:
			
		

> Also what media is recommended within the filter? would this have any impact on the algae ? currently there is a coarse foam, ceramic tubes and carbon in the three layers(default items that came in the filter kit).  But again the more I read it seems Carbon isn't great when adding fertilisers, should this be removed, what should go in its place ?


Use any media you want. If you need to improve flow/distribution in the tank, which by the way, is 5000X more important than media type, then you can remove some of the media which significantly reduces hydrodynamic drag in the canister and improves flow throughput. Carbon is great and in fact it's so great that you can remove everything else in your canister and replace it with carbon. Carbon has very little effect on fertilizers and whatever effect it does have, so what? Just add more fertilizer and be done with it. Carbon does 100X more good things than bad things.



			
				Tebo said:
			
		

> The problem I have right now, there is too much information on this site and its difficult to know the right direction to move forward with it as to what is relevant to my situation.


That's why you need to go to the Tutorial section of the forum and read every article there. These are the summary of the basic truths that we have discovered over the years, and these procedures work well despite the propaganda published in many places such as in LFS.

Cheers,


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## clonitza (17 Oct 2012)

GDA on glass is not really a bad thing unless you have a bulky top you can't remove to have access and scrape the algae.
Usually a thin layer of biofilm forms on glass and hardscape, depending on the level of organic matter in your tank, that gets covered in time with algae depending on the level of light the higher it is the faster it gets covered. 

The best way to avoid it is to:
- limit the water pollution triggered by unhealthy plants, give them all they need, nutrient wise.
- even the flow around the tank, try and minimize the dead spots, hardscape blocking the flow etc.

A picture with your tank would be nice without providing one I can give you only general advice.

P.S. Ferropol has only micro nutrients you also need to dose macro nutrients (nitrates, phosphates) unless your tap water doesn't have plenty of them.


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## Tebo (17 Oct 2012)

Thanks for the great feedback.

I will give up on the FX5 plan, and go with ordering another 306 to match what I already have and run them in parallel.

I will also get the EI starter kit asap, and use this instead.

As for the hood, yes its a bit bulky, its an oak one so not quick to remove, wouldn't want to do it on a frequent basis.  

I will take a picture on the weekend when it comes out of blackout, so you can get a better idea of whats going on.

I will get myself over and spend more time on the tutorial section improving my knowledge, many thanks for the pointers so far.


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## Tebo (1 Nov 2012)

Sorry for the slow reply, it's taken a couple of weeks to get the bits sorted and installed.

Here is a pic of the spray bar across the back, currently fed by a fluval 406 and 306.






No loose items sit on the bottom of the tank anymore, everything appears to keep moving.

The last week I ran the lights on 35% I have now raised them up to 45%.

Dosing daily with micro and macro from ei starter kit.

Looking a lot cleaner now, a small amount on the top of the stone and also topside of branch, although it does seem to be less daily, maybe the Pleco are eating what's left?

Co2 is now back on and getting back to green, will monitor and see how it goes, I expect to raise the light a little more in the next week.

If you need pictures from another angle please let me know.

Thanks


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## ceg4048 (2 Nov 2012)

I wouldn't be in such a rush to increase the lighting. What's the hurry? Increasing the light will not make your plants recover more quickly.

We assume that the holes in the spraybars are pointing straight ahead or very slightly upward?

Cheers,


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## Tebo (2 Nov 2012)

Yes the spray bars are pointing just slightly upwards causing the surface to ripple, I would say around 90% of the width is covered by the spray bars now.

If there is no driver for me to up the lights then I will hold off, I thought it would improve plant growth, but the leaves on everything appears ok at the moment. I guess the ferts have helped here.

Thanks


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## REDSTEVEO (2 Nov 2012)

On a more positive note :idea: now that you realise you don't need all three of those 1000 ND Grobeam Tiles maybe you might have one spare for sale?  

Good luck with the GDA if there is a way to sort it you will find it on here!

Cheers,

Steve


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## Tebo (2 Nov 2012)

Hmm don't plan to sell one at the moment, I have a plan for some shrimp tanks in the near future.  I think aquatics live will fuel the next steps for that, hopefully plenty of inspiration there for me to pick up ideas from.

The gda is certainly looking a lot better now after the great advice I have had, got some more moss arriving today so looking forward to get that in there too.

Thanks


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## ceg4048 (2 Nov 2012)

Tebo said:
			
		

> ...If there is no driver for me to up the lights then I will hold off, I thought it would improve plant growth...


Adding more light coincidentally improves algae growth twice as much, so you should always think twice about adding more light. (I think someone should make a nursery rhyme with that)



			
				Tebo said:
			
		

> ...I guess the ferts have helped here...


All the changes you have implemented have helped...EXCEPT the bit about adding more light....

Cheers,


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