Why are my 'easy to grow' plants suffering?

[Wolfenrook]

To go back to the question regarding daisy chainng your bottles when using DIY CO2, I run DIY and 'daisy chain' 2 x 2litre pop bottles. This does indeed help to keep a more stable output of CO2 going, however it is still nowhere near as easy to manage as pressurised CO2, so requires almost constant monitoring with steps taken when swing occur. The main reason it helps is because it allows you to stagger refills, start one bottle one week, the other the next and this way you always have at least one bottle going at full tilt. However it does nothing to reduce instability caused by things like temperature changes in the room they are kept in. for example when the room is colder CO2 production slows, when the temperature is higher it increases. I try to keep on top of this by having a Fluval 2 internal stuffed with filter floss in addition to my external (it helps with circulation as well), when the CO2 levels are getting too high I raise this filter higher in my tank, increasing surface agitation and so helping to drive more off. You also get a spike in CO2 with DIY when you first change the mix in a bottle. However 2 or more bottles is always better than 1, if it's a smaller tank just use smaller mixes in more bottles, just don't expect to be able to get perfect control of your CO2 levels.

DIY basically is better than no CO2, but it is very 'inconvenient' to use (read pain in the ...).

My advice would be that if you can scrape £66 together get yourself a JBL easy set1 off ZooPlus, it's the cheapest initial purchase price I have found but comes with the long term costs of having to purchase disposable 500g bottles at £10 a time, but at least you wont have to find somewhere to refill your bottles for you. My wife and I however have decided to find the money to buy a 500g refillable set from LunaPet on eBay, and at least with these you can always use a CO2 FE if it comes to it.

Ade

PS. Using DIY I currently get some green beard algae growing on wood and a bit on the substrate, but I find it does not detract from the looks of the set up, and my fish and shrimp love it! My dwarf gourami build their bubble nests out of the stuff! What it does do however is clog up the intake on my filter, thanks to the gourami dropping lumps of it everywhere.... I don't however get ANY cyanobacter or brown algae, and absolutely no algae on my plants.

 

[Tresbling]

Thanks for the input- I will try the staggered 2 x 2 litre bottles for the time being, I think it would raise my CO2 levels and stabilise them alot. My injection method involes just a tube running to under the impeller so each bubble is smashed up- alot escapes as big bubbles but as the flow is good, the tank is still always full of microbubbles. My bottles are inside a fridge (turned off, its my tank stand!) so thermal insulation is good (till i open the door).

Perhaps I will move over to pressurised as and when i get tired of putting sugar in bottles, but at the moment my plants have never looked better, and if it ain't broke...
Also the idea of buying into a refill system puts me off somewhat, paying 10 jib for something i breathe out seems a bit much!

Whats a co2 FE btw?

And about light calculators, perhaps that was a bit ambitious! What about width and depth integrated wpg (assuming the lights run lengthways from end to end)? Am i right in thinking that the wpg guide just goes wrong because small tanks are generally shallower and narrower?

Today I only ran 1 x 11 watts and the plants arent pearling but the fish are much happier and not hiding

cheers

 

[ceg4048]

Hi Tresbling,
Pressurized systems have a much greater significance than just the convenience of not having to deal with sugar filling. With a pressurized system you can drive your CO2 to much higher levels (which can be toxic) and it can enable you to grow more advanced plants at much higher growth rates. You can also program it's ON/OFF cycle and achieve better regulation as pointed out by Wolfenrock.

Adjusting wpg for different parameters is probably also in the "Just Too Hard" category. It's better if people simply learn about lights as well as all the other aspects of plant husbandry because that's what we are here to do. WPG goes awry partly due to the energy falloff as a function of the distance from the light source. While there is a linear change in volume as tank size increases the distance from the bulb does not scale proportionally. It changes proportionally to the cube root of the volume because volume is LxHxW, a cubic function. So, the tank volume is cubic, the photon energy dissipation is inverse square and the wpg is linear. It's bound to fail.

It's discussed a little bit more in this thread +> viewtopic.php?f=21&t=1697"

Another thing is that although pearling is a seductive phenomenon don't use it exclusively to gauge the health of your tank. You can add more CO2 to get more pearling at that lighting level but this isn't necessarily good for your fish. You can always add more light and more CO2 later on but for the moment it's better to stabilize the tank and to have no algae and decent growth.

Cheers,

 

[Wolfenrook]

Sorry for the abbreviation, CO2 FE = CO2 fire extinguisher. A lot of folks on here use 2kg fire extinguishers instead of proprietry CO2 bottles as they can get them cheaper and refilled for less outlay.

As to plant growth, I to get astounding growth using DIY CO2, I have to prune some of my stem plants twice a week! My concerns are not about how well my plants are doing, but rather about the almost constant peaks and troughs in CO2 levels that I have to contend with using DIY, not only because of the effect this has on algae, but also quite simply for the health of my fish! When I first change one of the bottles the levels spike so highly that my drop checker can turn bright yellow in less than an hour! This really isn't a good thing, and I can't always get to the tank to move my internal filter when this happens as fast as I would like to. Even with extreme measures like using a temperature controled water bath and multiple bottles, keeping your CO2 levels constant is going to be a battle with DIY. Then there is the need to find a way to make sure that your night time levels don't get too high in some cases, often leading to the use of noisy air pumps or additional water pumps. In fact, I would say that to get enough control on a DIY system could probably end up costing almost as much as purchasing a cheap pressurised system. Heck my DIY setup cost me about £10 to make (diffuser, air line, 2 bottles of Pepsi, silicon sealant, 2 anti return valves (I use 2 as the ones I have seem to actually be able to stop gas from a more active bottle making it's way into the less active bottle in any quantity), T valve, bag after bag of sugar...). It's actually shocking just how much CO2 I can get it to output, to the point where if I take the cap of the valve it gives off a loud hiss. The problem is come cold weather or very hot weather (to high a temperature slows yeast down, and can even kill it) output drops, and in warm weather it can sky rocket very quickly.

It's an issue of control. With DIY you will only ever have an illusion of control, it's those little critters who are really in control.

Ade