# Surface ripple in low tech or no surface ripple?



## Matt Warner (14 Jan 2014)

Hi everybody sorry I haven't been on here for a while its been very hectic the last 6 months with moving house and stuff. I was wondering whether surface agitation is a good thing in a low tech tank to introduce co2 or a bad thing. I always thought that with low tech you had virtually zero agitation son as not to gas off any co2 which is in the water already. Any input would be great. many thanks!


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## Alastair (15 Jan 2014)

Hiya matt good to see you back. 

When I originally ran my puddle tank low tech I had no surface agitation just slight movement and plants did well but due to a film developing I raised the outlet so I got agitation and the film cleared but plants also grew much healthier and thicker. 
Ive had agitation in all of my tanks now and have a fair amount in my big tank and everything is doing great.


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## darren636 (15 Jan 2014)

Why wouldn't you want surface ripple?


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## Matt Warner (15 Jan 2014)

Thanks Alastair. I might try aiming the filter outlet more towards the surface then and see if the plants grow any faster. I was just always under the impression that in a non co2 tank, surface agitation was a bad thing in regards to plant growth as you can't keep what little co2 you have in the water.


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## dw1305 (15 Jan 2014)

Hi all, 





Matty1983 said:


> I always thought that with low tech you had virtually zero agitation son as not to gas off any co2 which is in the water already.


 I agree with Alastair on this one, it is quite difficult to measure dissolved gases_ in situ, _but I'm reasonably confident that during the photo period having a large gas exchange surface (so a "ripple") actually leads to higher rates of CO2. 

Have a look at this thread, (and linked threads): <Maxing CO2 in Low Techs | UK Aquatic Plant Society>.

cheers Darrel


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## pepedopolous (15 Jan 2014)

I don't have a low tech but I think I would use an Eheim Skim 350 in any aquarium from now on. If you don't mind the extra equipment, it provides a nice ripple (but actually from the surface water being sucked in), and you don't have to worry any more about scum.

P


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## Andy Thurston (15 Jan 2014)

pepedopolous said:


> I don't have a low tech but I think I would use an Eheim Skim 350 in any aquarium from now on. If you don't mind the extra equipment, it provides a nice ripple (but actually from the surface water being sucked in), and you don't have to worry any more about scum.
> 
> P


 You just have to worry about shrimp instead


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## Matt Warner (15 Jan 2014)

Thanks guys this is very interesting. Is this a recent discovery in the planted tank world because I've only just recently heard that surface agitation in a low tech tank is beneficial to the plants.


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## darren636 (15 Jan 2014)

Matty1983 said:


> Thanks guys this is very interesting. Is this a recent discovery in the planted tank world because I've only just recently heard that surface agitation in a low tech tank is beneficial to the plants.


 It will increase co2 for the plants and increase o2 for the fish = win win.


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## three-fingers (15 Jan 2014)

I think it just depends on the method, as if it's an aquarium set up using the Walstad method with no ferts, a soil substrate, limited water changes, leaf litter ect. it could potentially allow for a greater-than-equilibrium level of CO2 within the water column, thus faster plant growth.

However, whether or not this is desirable is a good question!  Nowadays, with modern methods, I'd rather have the low-but-_stable_ equilibrium CO2 concentration from surface agitation, as opposed to a high-but-fluctuating concentration from decomposing DOCs and the like.  More reliable results from what I've observed .


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## Matt Warner (15 Jan 2014)

Well I've pointed the filter outlet slightly towards the surface causing a ripple. I will let you all know what happens and if I notice a difference in the plant growth. Many thanks


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## Tim Harrison (15 Jan 2014)

Like Alastair and Darrel, I prefer good surface agitation too. As Darrel said it's hard to quantify the effect it has on CO2 levels, but it is conceivable that it keeps them fairly constant during the photoperiod.
But aside from that it has other obvious benefits not least of which is higher O2 levels and healthier critters, and as Alastair mentioned a reduction in surface film. If you're using a soil with a high organic matter content the process of decomposition will provide your plants with a source of carbon anyway.


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## dw1305 (17 Jan 2014)

Hi all,





Troi said:


> but it is conceivable that it keeps them fairly constant during the photoperiod.


 I'm pretty sure Troi is on the right track, but I think even with lots of flow ("large gas exchange surface") the added CO2 is likely to be depleted pretty rapidly by photosynthesis during the light period. I don't have any empirical evidence, but  I've used pH and DO meters to measure the DO levels of the lab. tanks (heavily planted and fairly soft water) during the photo-period, and pH is ~pH8 and the oxygen saturation ~ 100%.

Again I haven't measured pH/DO at the start of the light period in the lab. tank, but I would suspect that the pH would be nearer pH6.5 ~ pH7 reflecting a higher level of CO2 and lower oxygen concentrations.

cheers Darrel


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## Andy Thurston (17 Jan 2014)

dw1305 said:


> Again I haven't measured pH/DO at the start of the light period in the lab. tank, but I would suspect that the pH would be nearer pH6.5 ~ pH7 reflecting a higher level of CO2 and lower oxygen concentrations.
> 
> cheers Darrel


Could/would you? just out of interest, you don't see that much ph data for low tech tanks


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## scrud (18 Jan 2014)

I always ran my old low tech tank with surface agitation as the plants seemed healthier that way.


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## dw1305 (19 Jan 2014)

Hi all,





Big clown said:


> Could/would you? just out of interest, you don't see that much ph data for low tech tanks


 I will do, I'll probably need to do it on on of the tanks at home over a weekend. 

cheers Darrel


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## Matt Warner (20 Jan 2014)

Well I've had the surface ripple now for a few days now and have already noticed a difference. The plants seem to be growing faster and more healthy. It could just be me but there definitely seems to be an improvement.


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## Richardbunting (5 Apr 2014)

Out of curiosty has changing your filter outlet height made a noticeable difference to the overall health of your aquarium?


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