Should I start using Excel?

Up until now, I've avoided use of Excel since I can't get it locally, and mail ordering costs a lot in shipping. But now that I'm going to start a saltwater tank, the cheapest way for me to get salt is to mail order it. So the additional cost that it would incur to buy Excel at the same time would be somewhat negligible. My 30g tank has diy co2, but it fluctuates a lot (between 10 - 30ppm); and more recently I've had repeated outbreaks of brush algae and I know this is why. Will adding Excel to this tank help solve this problem, even if the diy co2 continues to be somewhat sporadic? If I decided to stop dosing Excel, would I see any withdrawal issues such as when you stop injecting co2? Any other drawbacks to using Excel?

 

Good suggestions. I have tried to find wine yeast and haven't been able to yet, but I'll keep looking. I use a small desk lamp to provide heat, it really works great for keeping production going. My reactor probably isn't at 100% efficient, but it works well for distributing the co2 around the tank. It's an internal filter that has an inlet for airration, which I use for co2 instead. The impeller chops up the co2 into very tiny bubbles and then the output shoots them across the tank, this in addition to my hob main filter provides fairly good circulation, I keep my tank very full so the hob doesn't splash.

I find that I don't have a problem using up 2 cups of sugar in one 2L bottle, provided I add another tsp of yeast after a week or so (it seems that they run out of some nutrient or another after a week and slow down). How do I know it's being used up? I taste it before dumping it out. But if I add 3 cups of sugar, it will stop producing before the sugar gets used, and won't get started again. So I stick with 2.

My major issues with my diy have to do with either my not realizing it's slacked off quickly enough (out of town, etc.) or forgetting to turn the light on. For the first night after refilling, I can leave the light off, but after that night, I have to turn it on, or else it seems to slow down and not get going again.

 

I only have 2 - 2L bottles. If I don't add more yeast after a week, the only alternative I have if I want to keep co2 levels high enough is to change out the entire bottle after one week. Since adding more yeast keeps it going for the second week, and it's cheaper and easier, that's what I've started doing. If I had larger bottles, or more of them, it would probably be a different story. It doesn't totally stop producing after a week, but just slacks to the point where my drop checker goes to a darker green. Then I know it's time to add more yeast. I try to stagger them - so that every week I'm adding more yeast to one bottle, and changing the other, this keeps the production stable and reasonably high. With 2 - 2L bottles, I can't let them go for two weeks without doing anything, my co2 levels just drop way too low, production slows too much.

My hypothesis that the yeast start dying off due to a lack of a nutrient is because I have observed that adding more yeast causes production to increase for a week. Therefore, the slack of production of the initial yeast can't be from ethanol poisoning, and can't be from a lack of sugar, or the second batch of yeast would also be affected; therefore it must be an nutrient of some type or life span that simply runs out to a large extent after a week.

I don't use a check valve either, I found that it would clog with water and stuff after a short time. I have a screw-in shut off valve that I just shut off when I'm removing a bottle to ensure the water doesn't back-siphon. The rest of the time, it's a closed system, so water can't back siphon anyway.

 

There is a bit of a difference in production between when I have a new bottle and when I add more yeast. With a new bottle, the production is such that I'm really wasting it - some bubbles are coming out too big and going to the surface and breaking right away. But that's ok, because my drop checker turns a light green. So it's really overproducing at first. Then it seems to level off for about four or five days where my drop checker is a stable green. After the sixth or seventh day, the drop checker starts to go a bit darker, not blue but getting in that direction, then it's time to add more yeast (if I do this right away, I don't have bba...if I wait too long, that's when I get trouble). After I do this, I get massive overproduction once again, but it only lasts for a few hours this time, then it settles down to a stable green color again for another week, give or take a day or two. Then if it starts slacking again, I just change out the whole bottle.

That's all being said as if I did both bottles at once, not staggering them (which I have done sometimes). If I stagger the bottles, I get a more stable production. I guessed 10 - 30ppm, not because I can't keep it more stable than that, but because in reality, I occasionally don't recharge my bottles on time so it drops down to the 10 level. But if I keep on top of it all the time, it probably stays around 20 - light green to green on my drop checker. As long as I keep up to the green level, going higher doesn't make much difference. It's only when I go into the darker green that I have trouble. My problem is that life gets away from me.... and suddenly it's been two weeks, and I haven't done any bottle maintenance. I only have 2wpg so it's a little forgiving.