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My venture into my new 760 ltr planted tank .

Clive,

Your sump is therefore out-gassing both of these gases until each reaches their independent equilibrium concentrations. Oxygen has a lower equilibrium concentration than CO2. So really, your sump, if exposed to atmosphere is acting as a vent. Ideally, you'd want the sump sealed against atmosphere until the concentration of O2 fell to at or below atmospheric equilibrium concentration level. Only then would it actually add O2. Since there is no inexpensive way to monitor and control this, I would seal the sump and leave well enough alone. You want to delay the out-gassing of CO2 because this makes it easier to get the CO2 levels up to optimum levels before lights on. The penalty is that O2 levels may fall below equilibrium levels - but higher CO2 levels will enable the plants to more easily replace the O2.

from what I've been told it's 8 mg/l is the equilibrium level for water (of course this depends on temperature and altitude etc), but let's take that as our figure to work with. So no matter how much splashing around one does, this level cannot be increased since it's the equilibrium level. Is it true that planted aquariums can shoot that level over 10 mg/l, plants would be a different matter since they are injecting the water with O2?

From Simon's setup all I see is a closed sump. To me, it's basically a canister filter with an easier cleaning arrangement, but you do have the water surface of it that is in constant motion that contributes to the gas exchange if a difference occurs. Most of the vigorous splashing around might come from the feed if there is gurgling there.

What I want to ask is if it's worth the while to get a trickle tower involved. It's a more potent form of biological filtration since the bacteria will take the oxygen from the air and not the water. BUT, if the water is already saturated to over 10 mg/l by the plants, oxygen will get degassed from the water in the process along with CO2 if we have to inject the tower with air (which we do to make the tower work effectively, if we seal it, it just acts like a submersed filter).
 
Yes, there's a Catch-22 with trickle filtration or any system exposed to atmosphere. In a fish only tank it's a no-brainer. As the O2 levels drop due to fish respiration, the dry area, as you say, feeds the bacteria and aids in replenishing overall O2 levels. Such a tank would also use air bubbles or other form of surface agitation in the main area to speed up O2 equilibrium.

With healthy plants, an open dry area out-gases both O2 and CO2 so ideally you could have a powered valve that vents the tower to atmosphere only during late night/early morning and closes just before CO2 ON time. In this way you'd keep O2 levels up and minimize CO2 loss. This is a lot of added complication though, so really you'd only need to worry about this when you have high fish stocking levels. I try to keep things simple, so if you are not having issues with fish then it's better to seal the trickle's tower and accept that it will morph into a submersed filter. Whatever gasses (produced by injection and photosynthesis) that come out of solution in the tower are trapped and will diffuse right back in if the gas concentration levels in the water fall lower than what is trapped in the tower. I don't think it's necessarily worth going out of your way getting a trickle filter because of this issue, but it's also not worth worrying about if you are already using one, because you can always choose to seal or vent the tower as necessary.

CO2 out-gassing and the other downstream effects of an exposed dry area/sump have different levels of severity depending the individual tank, and so venting/sealing has to be evaluated on the relative merits. In Simon's case he has an issue with excessive CO2 loss which may be attributable to sump size, agitation within the sump, inefficient diffusion technique or any combination thereof. This results in an unreasonable gas consumption as well as possible poor distribution in the tank proper. In his case, sealing the sump helps mitigate the loss and produces better saturation of both gases generally. He has no fish yet so that part of the equation is yet to be determined. In some other tank the combination of factors may not result in as severe a loss, and so a vented tower or sump may not cause as much trouble.

Open top tanks suffer the same problems, because the surface is exposed to atmosphere, but many of these tanks are smaller, so the magnitude of the problem is minor enough that these issues may go undetected. It's important to note that this is a serious Mandingo sized tank, so whatever issues there are tend to get magnified immediately. Issues with which nany and pinky tank owners routinely skate away with are unforgiven in monster tanks.

Hope this helps...

Cheers,
 
that this is a serious Mandingo sized tank
That made me laugh. I'd never considered that open top tanks suffer the way that the sump does. I knew that had better gaseous exchange but I'd never considered what that really meant. Makes me really wonder what the ideal injection method is. Makes me wonder what would be better for flow too, I'd read about mazzi and eductors but don't know if they're a gimmick that wouldn't really do anything for injection levels in a tank.

How's the tank coming along simon? is everything doing okay or is the co2 effecting things negatively?
 
Clive,

It was a long time since I read Thiel, but he stated that biological filtration takes a lot of oxygen, it's just that I don't have the laboratory equipment to find out how much.

When you say the plants supporting the fish etc, it's not only the fish but also every other oxygen consumer in the tank, and I'm just wondering how much oxygen the biological colony takes in relation to fish mass. I can't see a linear relation since some fish are more energetic than others etc. .

My point is if the plants produce more than enough, and can saturate the tank to level not possible by exchange with the atmosphere, having a trickle tower would be pointless unless you are lacking O2 during the night time. But we also got to make the observation that there probably is less oxygen demand in the night time anyway, apart from the change of demand from the plants, since most of the fish slow down, and no feeding takes place to add to the load.

I don't like using large canisters for large tanks, opening and cleaning them would drive anyone crazy if they had to do it every fortnight.
 
Hi guys and Girls.
Sorry for no posts recently. Just so busy with other things.
Tank is coming along. Some is good and some is not.
I will post some pics of where I am. Lots of things need sorting. I am sure I need more/ better Co2 or better distribution.
I am trying the spray bar firing straight down at the moment. I am sure the position of this in my tank when I get it correct will improve things no end. I certainly have plenty of flow. I am thinking of increasing the hole size even more to reduce the pressure. I do not want to add more C02 just use it better. My weirs could do with improving more to reduce O2 being added.
also sunlight is not helping. I have covered the front of the tank throughout the weekdays until I get home at 5pm.
This helps I am sure. I get so much daylight where it is.
Talk later, things to do
Simon
 
Actually the O2 consumption is also a function of the amount of waste in the tank as well, and that happens 24/7. That's why reefers worry so much about measuring Redox potential. So the numbers can depend on how much you clean the tank. There are quite a few variables, really, too many to chase. If we do the things that we know have a strong impact on available O2 levels and on plant health then I don't think it's so important to get wrapped around the axle. Lots of large water changes, adequate CO2, good flow/distribution and so forth. This makes the choice of filter type less critical.

I use two 2080's on my 600L. What's the difference between cleaning a canister and cleaning a sump? I only clean one at a time, never both so this saves aggravation. This unit has wheels and handles on the trays I lift the trays out, hose them down and reassemble. A piece of cake really. By the way, for those technology anoraks, these are the more important design features of a filter, not whether it has silly microprocessors or programmable tsunami wave functions or whatever.

Cheers,
 
funny, I was about to mention rotting waste as well. And having it trapped in our filters is not a good thing. With a sump arrangement like Simon's he just takes the sponges out, gives them a scrub and rinse and puts them back in again. With a canister filter I have to disconnect, open the sealed unit (quite heavy from being contained with water), take stuff out, put it back in etc . . a lot of grief. My trickle arrangement for my fish only has a syphon box and it's the main mechanical filter part. I just turn off the return pumps, wait for water to stop overflowing and replace the filter floss and I'm done.

I don't agree with all this electronic silliness either, what a waste of space. And the new Fluval G3's are a total joke. Nice to look at though - they can probably do a 23 litre tank!!!

The idea of the sump setup was to separate the biological media and make it maintenance free. We do this by making the mechanical filtration openly accessible. With a canister it's unfortunately bound in with the biological media. I suppose that's the one thing about the G3 filters that I do like, it allows for rapid clean out/replacement of mechanical filter.

When you clean out your canister filter all you should be cleaning out is the mechanical filter to get the trapped detritus etc out, the biological media should never be touched. But from experience canister filter gets caked up with detritus if not properly maintained. The sump arrangement makes sure that it's easier to do and is a much better way of doing things if you've got the space and understand how to engineer it.
 
Lots of things need sorting. I am sure I need more/ better Co2 or better distribution

im just thinking that my 860 litre used a fraction of the co2 you seem to be using i dont think it is all down to planting types because initially i had a lot more stems. I think it must be more down to distribution, but the spray bar design appears to be very good. Perhaps sump wise?
 
Re: Trickle filters and oxygenation

Hi all,
"But from experience canister filter gets caked up with detritus if not properly maintained. The sump arrangement makes sure that it's easier to do and is a much better way of doing things if you've got the space and understand how to engineer it......" & "...... It was a long time since I read Thiel, but he stated that biological filtration takes a lot of oxygen, it's just that I don't have the laboratory equipment to find out how much."
I used to spend a lot of time looking at factors like B.O.D http://en.wikipedia.org/wiki/Biochemical_oxygen_demand and Redox potential http://en.wikipedia.org/wiki/Reduction_potential (when we were working with the landfill leachate). One of the very obvious out-comes of this was that a trickle filter offers vastly more biological filtration potential than any other type of filter, primarily because of their large gas exchange potential (both O2 in and CO2 out). The combination of a an easily cleaned mechanical pre filter (either by sedimentation or a capture in sponge) and a planted filter also helped. Unsurprisingly the "gold standard" filter system is a mechanical pre-filter, a planted section (either part of the filter (the deBruyn filter http://www.aka.org/UserFiles/File/debruyn_filter.pdf or similar) or as hydroponics) and a trickle filter. Another out-come was that the different biological trickle media behaved in a similar manner, and something like "Alfagrog" or "Hydroleca" combined being cheap and effective, I think ceramic rings came out marginally best. (However in a system with lower BOD, sintered glass ("Siporax") may offer advantages .

I wrote an article for about this (for a specialist L. No. keeping forum) a while ago. It has had a number of homes (which is why the HTML is a bit mangled), and at present it is at: http://plecoplanet.com/?page_id=829, (but I'm not sure what the access is like to this if you aren't a PP member). One of my aims in writing it was that a lot of plec. keepers realised that flow, biological filtration and oxygenation were really important, but were stressing (or even killing) their L. numbers by assuming that a bare tank bottom and ever larger canister filter would take care of cleanliness, biological filtration, gas exchange and flow. Another aim was to try and get people to use plants, as very few keepers had planted aquaria, and many didn't appreciate how important they are in the maintenance of water quality.
I don't agree with all this electronic silliness either, what a waste of space
Couldn't agree more, I still post occasionally on PP (usually on the filtration threads), explaining why an EHEIM classic is still the best canister filter. I now use Clive's immortal phrase "pump in a bucket" to explain why you all the electronic gizmo's are unnecessary.

cheers Darrel
 
another thing that's just occurred to me is that trickles filter, especially those with rotating spray bars and DLS, get the media UNIFORMLY wetted due to the gravity forcing effect. Channeling is virtually non existent, this make for an extremely efficient use of the biological media.

With a submersed biological media, or if it's in a canister, there are possibilities that water, because it always seeks the path of least resistance, will channel through the media, especially when things get caked up with detritus.

Because of the way an canister filter is designed there is channeling to a certain degree. I know this because it's always the area of the filter floss near the inet at the bottom of my canister filter that will get caked up with detritus first.

This also explains why trickle towers are much more potent as biological filters.

I rather wish Fluval made a large version of their G6 where open access to clean out the mechanical stage is possible, so that we never have to touch the biological stage or worry about its integrity.
 
I use a trickle tower on my Koi pond . Its simply a 4 ft tall water butt filled with Boi Balls. Has worked a treat for years and I have never touched it. Its prefilter is a Vortex chamber off the skimmer filled with brushes. Once a month cleans that out.
 
Sorry for the delay. Had so much else on.

SG1L2802Medium.jpg


SG1L2809Medium-1.jpg


Generally I think its going ok. Its not all dead and I cut a bucket full of stem growth off this morning
I do now have a few problems.
From what I have read and observed I still have a problem of getting the Co2 to all the plants.
The ones at the front are the worst. I have no idea on how best to improve that. also I am not sure if I am feeding enough.

SG1L2808Medium.jpg


SG1L2807Medium.jpg


What do you think.

Simon
 
Simon, are theses leaves with the blotches old leaves or new? If they are old then just cut them off. It's the new leaves we are concerned about. Old leaves are terrestrial leaves. They are not optimized for submerged gas exchange so they will tend to suffer more. If new leaves look like this then you have a serious problem. I can't see any nutrient related issues in those shots. Why do you think you need more nutrients, especially after cutting bucket loads of plant material?

Cheers,
 
I am sure that would be on old leaves.
So do you also think there is a Co2 problem at the front of the tank. The brown Algae I am putting down to new tank syndrome ,although the system should be starting to get some useful bacteria by now I would hope. I am still running 1/2 power on the light. 3 water changes a week still.

I looked at day one pictures against week 4 .

SG1L2732Medium.jpg


SG1L2809Medium-1.jpg
 
Always Broke said:
I am sure that would be on old leaves.
So do you also think there is a Co2 problem at the front of the tank. The brown Algae I am putting down to new tank syndrome ,although the system should be starting to get some useful bacteria by now I would hope. I am still running 1/2 power on the light. 3 water changes a week still.
Well, you know I wake up every morning and my very first thought is always; "I'm sure I have a CO2 problem somewhere in the tank".

If your CO2 were absolutely perfect the terrestrial leaves wouldn't suffer so, but it's very difficult to get perfect so having CO2 be only "OK" will have to do. As I mentioned, if the new leaves aren't browning then I would leave it for now. Terrestrial leaves have a different physiology, including a thicker waxy cuticle and vascular tissues with plenty of air spaces optimized for atmospheric gas exchange. These don't do very well when flooded. CO2 has a difficult time traveling across this border.

The new leaves that grow in a submerged environment typically have thinner cuticles, or sometimes no cuticle at all. The epidermal layers might be thinner or missing. These new leaves are more like a flexible soft contact lens, much better adapted to living in an aqueous solution than to living in air. If these leaves are not browning or deteriorating then it means that the CO2 concentration at that location has not fallen below critical levels. As I mentioned earlier, simply cut off all the terrestrial leaves and that will be the end of the worry.

The diatomic algae are transient. As long as you don't go bonkers with the light they should only last a few weeks then disappear. It'll take a few months for the tank to stabilize so I wouldn't really worry too much. If you're not getting Rhizo, or Clado or GSA or BGA then I very much doubt that you have nutrient deficiency - that's no guarantee that you won't have problems later, but for now it's OK. If you're not getting filamentous algae then your overall CO2 is OK.

Is it just me or does your light look pink?

Cheers,
 
Silly Camera is making the lights look like that.
I will work on getting a bit better flow to the front of the tank. I will also have a big leaf cutting session later in the week.

Thanks Simon
 
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