CO2 Injection/Diffusion

[SQUEAK]

An interesting idea Freddy, I had never considered injecting solution straight into the substrate. However, wouldn't this mean that there would be simply concentrated 'pockets' of nutrients? I would think that water movement through the substrate is fairly minimal, at best. No more than using tablet form (or similar) I guess though...

It's worth a shot, right? Thanks for the advice!

[FC]

Yes, there would be concentrated 'pockets' of nutrients. However, the concentrated solution will move out by diffusion and would be dissipated in about 2~3 weeks.
Tablet/solid form (so far) do not come in proper/balanced formulae.
I do use tablet/solid form but I use liquid much more to gain better control over what I provide to the plants.

[SQUEAK]

Hello all,

News is basically all good. After lifting the blackout from my tank, all the visible algae was gone or dead - it was a simple cleanup operation from that :P. Hooray! Also, I've adjusted my powerhead to blast into a little 'cup' with the CO2 in it, and turned off my air pump. There is now no break in the surface water (although there is a mild current agitation, no ripples).

I think I will attach a bit of foam to the intake of the powerhead to get two birds with one stone, filtration and the CO2 diffusion. The gas that is being placed into the 'cup' seems to dissolve at fast enough a rate that it doesn't spill out. Maybe it's just in my head, but there seems to be some more growth in just the last 3 days - lets hope, no?

Take a look at this little beauty just for fun, directly from the tank... Hygrophilia Polysperma 'Rosanervig' (and no, those lines aren't photoshop )



I'd like to thank everyone who has helped me with this problem - I will try to post pictures of it tomorrow evening. The tank is looking a lot better, now to figure out how to keep it that way (and move back my killifish, who seem to have taken a real liking to their new tank...)

[FC]

Peter,
Congratulation!
The blackout is very helpful, indeed. I have a few suggestions:
Dissolving CO2
1) if possible, place the cup below mid height of the tank - to increase water pressure acting on the CO2.
2) I do not know how your filter foam looks like. If you can shape the foam such that the bottom form an inverted cup, you may consider bubbling the CO2 directly under the foam. The suction water flow there will help dissolve the CO2 and any undissolve ones will be suck into the pump and spray out like a mist. Note that the foam use should be coarse type.
Keep Algae Away
It is beneficial to dose the water column (use methods mentioned before) now.

[SQUEAK]

Freddy,

I will move the powerhead lower in the tank with the cup - that should solve that problem. I added a good dosage of Flourish into the water column after some cleaning, and injected it near the bases of plants (not directly into them, but a few inches away).

The filter foam is indeed the coarse type, however I don't think it would be feasible to make a bell out of it, the gas will just tend to pass through the openings in the cells, instead of getting trapped within. Right now, instead of the CO2 going into the powerhead itself to get 'mashed,' it empties into an inverted cup, and the powerhead directs a current through that. Seems to work, but time will tell I suppose.

[FC]

Hi Peter,
Typically, planted tank with fishes has insufficient Phosphate and Potassium, thereby, causing the plants in medium term (longer than 1 month) to suffer defficiency of these 2 elements. And weak plants invite algaes. Consider dosing, on top of Flourish, the NPK macro nutrients. If you do not like to mess with powders, try getting the newly available ready-mix Hagen NPK.
Note: If you do not change water frequently (like me), add also Magnesium and Calcium.
BTW, I hope you did change the water 100% after the blackout (to remove any stray algae).
Have fun!

[timebomb]

Loh K L, Freddy, or anyone with a diffuser similar to the one in Loh K L's picture, do you know approximately what the internal diamter of the diffuser is? My first concern with a straw is that the bubbles are not going to move through the straw very well (adhesion will cause it to stick to the sides, for instance), and I think the spiral straws in particular have a very small internal diameter.

Peter, besides the diameter of the spirals, the length of the diffuser and the distances between the spirals are also important factors that will affect the performance of the diffuser. A couple of years ago, I needed a short spiralling diffuser, something that can fit into a low tank. The diffusers in the market were all too long to be of any use to me. I asked for help and was amazed when my friend in India sent me a couple of very short spiralling diffusers. He managed to find a glass-blower in Bangalore who could "blow" a shorter diffuser out of the taller model that was shown to him. I still have the diffusers with me and although they aren't very effective, it's still a great piece of work:



For the life of me, I can't figure out how the glass-blower did it but his diffuser even comes with studs where you can put in the suction cups. The Drop-Checker looks easy but how on earth did they create the spirals? They say India is a great country for out-sourcing various kinds of work. The fact that they can blow their own spiralling diffusers (and at a very low cost at that) is testimony to this

Loh K L

[SQUEAK]

Hi Peter,
Typically, planted tank with fishes has insufficient Phosphate and Potassium, thereby, causing the plants in medium term (longer than 1 month) to suffer defficiency of these 2 elements. And weak plants invite algaes. Consider dosing, on top of Flourish, the NPK macro nutrients. If you do not like to mess with powders, try getting the newly available ready-mix Hagen NPK.
Note: If you do not change water frequently (like me), add also Magnesium and Calcium.
BTW, I hope you did change the water 100% after the blackout (to remove any stray algae).
Have fun!

Just clarification here Freddy,

You state NPK twice. In the first case, are you referring to the nutrients N P and K, or to the Hagen product 'NPK'? I understand in the second part that you are referring to the product, but I'm not clear in the first part as to which you refer to. If you are referring to the chemicals themselves, is there any desired 'ratio' to achieve with the chemicals, or is it more of the 'touch-and-go' style?

It looks like I will have to order the chemicals online. The only fish store near me has gone badly downhill these last two years, and has begun charging exhorbitant prices for sub-par equipment.

I did a large change directly after removing the blackout material (~75%), and since then have done another water change of about 30%, but not a water change of 100% all at once. Trouble brewing ?

Loh K L,

I understand what you are saying, and have considered that - the diameter was mostly asked for out of curiousity. I am however, exhausted - I have been at campus the last 16 hours, and tomorrow isn't looking like a good day either!

Have a good night all.

[FC]

Hi Peter,

For all mentions of NPK, I meant Nitrogen, Phosphor and Potassium.
For Hagen NPK, see below pic which is self-explainatory.

Visit their website, there is dealer information for USA.
http://www.hagen.com/usa/aquatic/pro...01076850020101

With regards to desired ratio to achieve with these chemicals, I studied them hard long time ago. The problem is the knowledge was not stored in my brain's "hard disk" and it was not "backed up", it was in my "working memory" which was purged few years ago . BTW, the concentrations to keep are:
NO3 - 5~15 ppm
PO4 - 0.5~2.0 ppm
K - 5~15 ppm

Key Points
1) It is not critical to keep close/exact ratio but to maintain the individual nutrient within the above said range. This fact applies to all fertilisers.
2) For any plants to survive (to thrive will need more than these), sufficient concentration of all key nutrients are essential. The key nutrients include:
Micro - Fe, Mn, Cu, Zn, Mo, cobalt Co & B.
Macro - N, P, K, S, Ca, Mg, CO2 (carbon being the main building block).

Others
1) Temperature plays an important part in the metabolism of the plant.
2) Light is the driver and in some objectives, it is used as motivator.
3) Water flows provide/transport/dilute/diffuse nutrients and facilitates biological activities.

[SQUEAK]

Hello friends,

It has been a while since I posted - several weeks. The blackout was a rousing success, and I've implemented some of the suggestions made in this thread - as a result, I've had growths of almost four times the original height of a couple species, most notably my cabomba and sessiflora species. Numerous other plants have been growing like mad, and even a couple runners being put out. A couple bits of algae have been starting to creep back in though... so fight, fight, fight against the recurrence of it :P.

Only problem... now that I have gotten my killifish into my 5.5 gallon tank, they don't want to get out! They are quite happy & settled into that tank now...

Finals start this week - so I don't have a lot of time to update. My most sincere of thanks to everyone who has helped out, or contributed their knowledge in some ways - I'm stunned every time I look at this tank.