_ReApEr's 29g: An Enigma

[_ReApEr]

Hello, everyone, first post here. Wonderful to have found the place, lots of excellent and uncommonly in-depth info here.

I am fairly new to the hobby, first tank started late last November, and I've just recently entered the realm of CO2. Three weeks ago, my tank was fairly significantly upgraded. I swapped out my two AquaClear 50s for an Eheim Pro II 2026, swapped a 150w stealth heater for a 200w ETH inline, and added pressurized CO2 injection in a "Rex Grigg style" reactor. I also switched from Flourish, Flourish Excel, and Flourish Potassium to EI dosing with KNO3, KH2PO4, K2SO4, and CSM+B. About a week after the changes, I had an onset of green water that I'm still battling. I'm having issues with a few things and am, frankly, getting a bit overwhelmed and discouraged. I guess I need some help prioritizing these things as well as how to actually tackle them. I absolutely love the hobby (I hardly do anything with my spare time but read up on it) and will stop at nothing to achieve what I want which, right now, is just a healthy tank. This is probably going to be a fairly massive post, please try to stay with me.

I suppose I should start with the tank.

Setup

• Tank: Standard 29g
• Lighting: Single Satellite Compact Fluorescent fixture with 65w dual daylight 6700K/10000K bulb.
• Filtration: Eheim Pro II 2026
• Heater: Hydor ETH 200w inline
• Thermometer: Coralife digital

CO2 System

• 5 pound aluminum CO2 cylinder
• GreenLeafAquariums Primo CO2 regulator
• GreenLeafAquariums drop checker
• DIY Rex Grigg style 15"x2" inline CO2 reactor

Flora

• Amazon Swords (Echinodorus amazonicus)
• Moneywort (Bacopa monnieri)
• Small Crypts (Cryptocoryne parva)
• Java Moss (Vesicularia dubyana)

Fauna

• 7 Cardinal Tetras
• 2 Neon Tetras (they think they're Cardinals)
• 2 Bronze Corys
• 2 Albino Corys
• 2 Flying Foxes
• 3 Otos
• A few ghost shrimp
• Who-knows-how-many Malaysian Trumpet Snails

Misc.

• Fertilization: Estimative Index - KNO3, KH2PO4, K2SO4, CSM+B
• Substrate: 60lbs. ECO Complete
• Two pieces of Mopani wood

I'll list all the things on my mind and then get back to them explaining why it's a concern and/or what I've done to try and fix it and whether or not that is/isn't working.

A) Green water
B) Drop checker always green
C) Surface film
D) Direction of Christmas upgrade
E) Potential circulation issue

Now to get down and dirty.

A) Green Water
Certainly, this is something that I, at least, think should be at the top of my priorities. It's been so bad, I can't even see a few inches into the tank. Thanks to the oh-so-famous ratio of pictures to words, here's a picture:

For those wondering, yes, that's Zelda in the reflection. LOL.

Anyway, after reading around these forums, I'm fairly certain it's a CO2 issue. My drop checker is green, indicating good CO2 levels, but I don't know if I can trust that (see "B"). I've experimented with different spray bar configurations for better circulation (see "E"). When I upgraded everything, I also changed the photo period from 8 hours to 10, but I changed that back to 8 last week. It's been going on, now, for about 3 weeks. I'm not sure what else to attempt or what to do about it.

B) Drop checker always green
To be redundant, yes, my drop checker is always green. By "always," I mean even all the way up to the morning when the CO2 turns back on, it's the same color green as when they turn off. 24 hours, it's the same color of green. I took it out of the tank and let it sit for a while and it turned blue, so it's not a solution issue or anything like that. I also tried increasing surface agitation a ton to promote off-gassing at night and purging the reactor right after lights went off so there wasn't any built up CO2 being dissolved all night. Nothing. I'm now running an airstone overnight tonight to see if that might help, but it's been 5 hours and it's still green. I was under the impression that having no CO2 and good O2 levels during the night were optimal, but I can't seem to get rid of the CO2. Is this important, or should I just be happy that my drop checker is green?

C) Surface film
I'm getting a surface film since not having the HOBs. I've read that there are two types: one of which is green, and the other is white-ish. I have the latter. It concerns me because I know it cuts light into the tank. I've tried a few spray bar configurations (again, see "E"), a couple of which attempted to take care of the film, but I'm satisfied with a configuration that does not. I was hoping the airstone I'm running in an attempt to off-gas CO2 overnight would, at least, break up the surface film overnight and leave a fresh surface for easy light penetration come morning. But the airstone does not seem to be helping with the CO2 and it's just creating lots of little splashes from the bubbles popping at the surface, which is splashing water all over the place and getting my light bulb wet. To stop that, I put the splash guard back on, but I don't like that it will inevitably diffuse some of the light before it gets into the tank. So, I'm thinking even if it does help a bit with the surface film, the negative outweighs the positive and I'll just ditch it anyway. Instead, I was thinking about buying a surface skimmer. What are everyone's thoughts? I thought about the Eheim Surface Extractor, but it's not directly compatible with the 2026, so I was looking elsewhere. Any ideas?

D) Direction of Christmas upgrade
Okay, for Christmas, I was planning on asking my girlfriend for a Catalina 4x24w T5HO fixture, which would bring my watts from 65 to 96. I have, however, read around the boards here that 65w PC is probably sufficient to grow the majority of plants perfectly fine. How much would I benefit from upgrading the lights, if at all? I was also wanting to buy some Borneo Wild tools, perhaps I should ask for those instead? I was also eye-balling the CAL AQUA LABS inline CO2 diffuser to replace the "Rex Grigg style" reactor I have now. Perhaps I should ask her for some Borneo Wild tools and the diffuser? I was even considering being crazy and asking for another Eheim to totally negate the possibility of a circulation issue (see "E"). Would that just be way overkill? With $200-$300, what would you guys recommend?

E) Potential circulation issue
This was a concern of mine for a bit, but I think I've got it under control. When I first got the Eheim, it had three segments for the spray bar. I configured them like this:

[--out/down--][---out/up---][--out/down--]

The out/up segment was to combat surface film. This was too much pressure in too few areas for my liking, so I added a couple segments:

[--out/down--][----down----][----out/up----][----down----][--out/down--]

Again, the out/up segment was for surface film. The down segments were to kill a dead spot in the back of the tank. This, however, was the opposite of the first: not enough pressure in too many places. So, I made this one:

[----down----][--out/down--][--(no holes)--][----down----][--out/down--]

That was pretty good, but I didn't like the little amount of movement towards the front of the tank. So, the current configuration:

[---out/up---][----down----][--(no holes)--][--out/down--][--out/up--]

I'm pretty happy with this one. The out/up ones in this one are at a less severe angle and, as such, don't do anything for the surface film. They're more just to get water moving all through the tank, top layers included. All of my plants are moving, although very gently. I don't know if there's supposed to be more vigorous movement or if just some, any movement is sufficient. If I should have more movement, I was thinking of getting a Koralia Nano. Thoughts? I am, by the way, just starting to experiment with moving my drop checker around the tank, though I'm doubting it'll ever show anything different being I've never seen it anything but green as long as it's in the tank.


So, now that that's all out of the way. Thanks for sticking around and making it all the way through. I'm really in need of some direction because, like I said, I'm getting a bit overwhelmed worrying about all of this stuff at once. Thank you so much for any and all advice in advance, I truly appreciate it.

 

[Philosophos]

Wow, that's an impressive algae bloom. Your CO2 isn't high enough. Green isn't enough, even with a 4kh solution in the drop checker. Push it until your fish seem annoyed with the circumstances (head towards the surface, heavy breathing) then back off until they're not stressed. That's your CO2 mark, and the solution to your problems long-term. To get rid of the bloom that you do have, I'd opt for a large water change and a UV sterilizer.

I've had surface film problems on and off. The best solution to the problem is to pre-soak your food at feeding time; phospholipids and protein from floating foods will accumulate on the surface more easily if they're left on the top to degrade there. The other big help is putting a very small power head near the surface of the water, or angle the flow of your rain bar enough to disturb it. Regular water changes are also a plus.

As for lighting, don't bother with the upgrade. Get yourself more even spread of lighting, or something else. You're running the exact same fixture that I am over 29 gal, and I don't have any real light based limitations for my growth. With the plants you have, you could probably actually go down to 1wpg and not have any trouble keeping those plants healthy.

Moving your drop checker around isn't going to let you get acquainted with it when you increase your co2. Keep it in a low flow area until your plant growth and flow dinamics are stablized, then use it to check problem areas.

-Philosophos

 

[_ReApEr]

Thanks for the response.

I'll start cranking the CO2. How long should I wait between each increase? A day? Two? A week? And I'll be sure to keep a close eye on the fish.

Regarding the surface scum, I did have my spraybar spraying at the surface, but it had to be so much agitation that it caused splashing before it actually did any good and the splashing was getting my light bulb wet. How would I go about presoaking flakes, exactly? Let them sit in a bowl of tank water for a minute, then add?

Since you have the same light fixture I do, how do you have yours set up? Mine is just up on its legs over the middle of the tank. What do you do for a good spread? And the reason I was planning on upgrading is because I'm also wanting to rescape, primarily to include a carpet, perhaps HC or glosso.

For the greenwater, I was hoping to avoid spending money on a sterilizer being most people say they're nice to have around but mostly useless and even problematic at times (causing precipitation of fertilizers). I forgot to mention that I'm doing daily 50% water changes in an attempt to keep the water clear enough for the plants to photosynthesize and maybe drive the algae off. Should I continue? If so, how will that affect my dosing regimen?

Thanks so much for the advice, very appreciated.

 

[Tom Barr]

CO2 dosing is more of an art, something that aquarists are careful with. We use data like pH/KH, drop checkers etc as tools to get close. Often they can mislead us some.

Still, if they do not produce the results we want and expect, we should not simply assume they are correct, and realize we are not getting the results we seek.

So we start with what we think they should be using something like those test methods, then slowly add more CO2. As CO2 and O2 are a two part process for fish health and vitality,, adding more CO2, or CO2 in general, should also include good current for fish and exchange of O2. We lose some CO2, but this matters not relative to the fishes" lives.


There is not good argument against that(unless you have no fish).

This allows more wiggle room to add more CO2.

Next you progress slowly and good response from the right amount of CO2 can take a few days, weeks even with some plant species. Other respond within hours(eg, Riccia).

Less light is a big factor also, less light = less CO2 demand= more wiggle room with adding CO2(and more wiggle room with nutrients/ppm's and location of nutrients).

High light, poor CO2, poor nutrients = excellent for algae.

UV's are great for GW(Green water). Micron filters are another option.
New plant tanks etc sometimes get GW, does not harm plants.

See if you can borrow or rent a UV even from someone.


Regards,
Tom Barr

 

[Philosophos]

I'll start cranking the CO2. How long should I wait between each increase? A day? Two? A week? And I'll be sure to keep a close eye on the fish.

As Tom stated, the plants can take a while for full response, and it's definitely an art unless you've got a $5,000 CO2 meter. I push for the start of fish stress, then scale back. Distribution is a huge part of things; making sure the flow keeps CO2 in every part of the tank possible. Needle wheel mods for power heads make it easy to get your flow right because you can see the bubbles. Reactors get a little more difficult.

Regarding the surface scum, I did have my spraybar spraying at the surface, but it had to be so much agitation that it caused splashing before it actually did any good and the splashing was getting my light bulb wet. How would I go about presoaking flakes, exactly? Let them sit in a bowl of tank water for a minute, then add?

I get a fine dusting like that now and then, but nothing too bad. Push it as far as you can without splashing, then set your CO2 to compensate for the surface disturbance. It will lessen the film if nothing.

I pre-soak in a cup using a little tank water; swirl it around a little.

Since you have the same light fixture I do, how do you have yours set up? Mine is just up on its legs over the middle of the tank. What do you do for a good spread? And the reason I was planning on upgrading is because I'm also wanting to rescape, primarily to include a carpet, perhaps HC or glosso.

I try to keep mine forewards somewhat; the plants in the back are tall, so they're closer to the light source anyhow. The challenge is getting light to the lower areas.

For good spread on a tank, I try to use as many bulbs as possible, spread out evenly or weighted towards the front if I can. Even doing two seperate bulbs is better than one. The main trick is not over-watting, that and getting a ballast that will let your bulbs last; programmed start are best.

For the greenwater, I was hoping to avoid spending money on a sterilizer being most people say they're nice to have around but mostly useless and even problematic at times (causing precipitation of fertilizers). I forgot to mention that I'm doing daily 50% water changes in an attempt to keep the water clear enough for the plants to photosynthesize and maybe drive the algae off. Should I continue? If so, how will that affect my dosing regimen?

I don't use one constantly. It's nice to have one around for the odd bout of disease or green water. Once you have one good quality UV sterilizer, that's pretty much all you need to take care of all your tanks.

As stated, you could go with the micron filter Tom is talking about; I haven't used them my self, so you'll have to talk to him about the details.

-Philosophos

 

[shoggoth43]

For the green water, you can try a siesta period and see if you can weaken the algae a bit. Basically drop the photo period to a few hours on, one or two off, and then a few hours on and leave the CO2 running the whole time. Plants tolerate this better than the algae. More water changes might tip the balance as well. You aren't going to win the green water fight with just water changes in all likelyhood.

Scum on the surface can be dealt with easily enough. Until you find out what's causing it, take a tall glass ( clean, no soap ) and slowly submerge it into the tank. Hold it at a slight angle so that the rim is only JUST under the water on one side. You can then watch the scum pour down into the glass as the surface water is dragged in. You may need to do this a couple of times and possibly daily. Once things settle down you will hopefully not need to do this as often. The surface scum will inhibit gas exchange. It may also explain your drop checker remaining green if there's scum showing up on the "water surface" inside the drop checker since it will stop the gas exchange. Certain foods really kick this up. For example, I've been feeding glass worms to my discus recently and it's very noticeable. Not nearly so much with pellet food.

Clean your filters. You may be overfeeding and stuff may be accumulating in the filter which won't help. REALLY tear it apart, I was stunned at the thick brown slime on the impeller and tubing in my cannister the other night. The Cal Aqua CO2 reactors are very pretty. Most people I've heard from who have one are extremely concerned about breakage so you may want to pass on that given that you've got what should be a fairly decent reactor already. If you want to go a different route, consider one of the needlewheel modifications in the DIY sticky threads.

As stated above, 65W is quite a bit of light. I've got 32W above my 29 biocube and I'm pretty sure it's way too much for me to get nearly enough CO2 in there. I'm also heavily pruning back and cutting out plantlets all the time and trying to ignore all the algae. If you can raise the fixture or diffuse the light you'll probably be better off in the long run until you get some more experience and a better feel for what is normal.

-
S

 

[_ReApEr]

CO2 dosing is more of an art, something that aquarists are careful with. We use data like pH/KH, drop checkers etc as tools to get close. Often they can mislead us some.

Still, if they do not produce the results we want and expect, we should not simply assume they are correct, and realize we are not getting the results we seek.

So we start with what we think they should be using something like those test methods, then slowly add more CO2. As CO2 and O2 are a two part process for fish health and vitality,, adding more CO2, or CO2 in general, should also include good current for fish and exchange of O2. We lose some CO2, but this matters not relative to the fishes" lives.


There is not good argument against that(unless you have no fish).

This allows more wiggle room to add more CO2.

Next you progress slowly and good response from the right amount of CO2 can take a few days, weeks even with some plant species. Other respond within hours(eg, Riccia).

As Tom stated, the plants can take a while for full response, and it's definitely an art unless you've got a $5,000 CO2 meter. I push for the start of fish stress, then scale back. Distribution is a huge part of things; making sure the flow keeps CO2 in every part of the tank possible. Needle wheel mods for power heads make it easy to get your flow right because you can see the bubbles. Reactors get a little more difficult.

Well, alright guys, I've increased the CO2 a good amount. My drop checker is now looking a little on the yellow side, just for reference's sake. My plants are pearling, though only from the areas they were trimmed last night, so I don't know if that's as good a sign as normal. The fish are not showing any negative symptoms of the CO2 increase yet, though I will be watching them for much longer than today. I've also turned my first section of spray bar a little further up to have a good amount of surface movement, but no actual agitation.

I try to keep mine forewards somewhat; the plants in the back are tall, so they're closer to the light source anyhow. The challenge is getting light to the lower areas.

Alright, I moved mine forward to about the one-third of the way back mark. That should give the foreground plants some better light.

I don't use one constantly. It's nice to have one around for the odd bout of disease or green water. Once you have one good quality UV sterilizer, that's pretty much all you need to take care of all your tanks.

For the green water, you can try a siesta period and see if you can weaken the algae a bit. Basically drop the photo period to a few hours on, one or two off, and then a few hours on and leave the CO2 running the whole time. Plants tolerate this better than the algae. More water changes might tip the balance as well. You aren't going to win the green water fight with just water changes in all likelyhood.

I'm going to continue fighting it with just daily 50% water changes and hope it does die off. I've had a nasty bout of it before and it did subside just by keeping on top of it with water changes. I'm going to try that again, but if it doesn't start showing signs of going away, I'll look into a UV sterilizer and, actually, per Tom's recommendation, I'm going to ask at my LFS if they happen to rent them.

Scum on the surface can be dealt with easily enough. Until you find out what's causing it, take a tall glass ( clean, no soap ) and slowly submerge it into the tank. Hold it at a slight angle so that the rim is only JUST under the water on one side. You can then watch the scum pour down into the glass as the surface water is dragged in. You may need to do this a couple of times and possibly daily. Once things settle down you will hopefully not need to do this as often. The surface scum will inhibit gas exchange. It may also explain your drop checker remaining green if there's scum showing up on the "water surface" inside the drop checker since it will stop the gas exchange. Certain foods really kick this up. For example, I've been feeding glass worms to my discus recently and it's very noticeable. Not nearly so much with pellet food.

Clean your filters. You may be overfeeding and stuff may be accumulating in the filter which won't help. REALLY tear it apart, I was stunned at the thick brown slime on the impeller and tubing in my cannister the other night.

Yeah, I've just been using a gravel siphon upside down and siphoning off about a gallon from the surface every day, and that's working nicely. My filter is only three weeks old, I doubt I have too terrible an amount of stuff built up yet. The pad, however, could probably use a replacing. I do think I was overfeeding, but not anymore. Perhaps that decrease and the addition of pre-soaking the food will help out.

The Cal Aqua CO2 reactors are very pretty. Most people I've heard from who have one are extremely concerned about breakage so you may want to pass on that given that you've got what should be a fairly decent reactor already. If you want to go a different route, consider one of the needlewheel modifications in the DIY sticky threads.

Looks like I'll be staying away from the diffuser, then.

I also think I will pass on the lighting upgrade, at least for now, and just work on getting things right before trying to make them better. Instead, I think I'll just go with some Borneo Wild tools, perhaps an external pump and intake/spray bar assemblies for some extra circulation.

Thanks for all the advice, guys. And more, if anyone has any, is always appreciated, too! I'll be reporting the CO2 increase results.

 

[_ReApEr]

So, today was the first day I had the CO2 increased. The fish, oddly, seem happier than usual. I don't know what it is. My drop checker was absolutely yellow by the time lights went off, and I mean yellow. They are not exhibiting any signs of stress, however. Should I continue increasing?

Thanks, guys.

 

[Philosophos]

Are you sure you've got 4kh water in that drop checker? If not then you could have your drop checker bright yellow 24x7 and it wouldn't make a difference.

If you do have 4kh solution in your drop checker, try leaving it there and see what happens; solid yellow is pretty high. If algae recedes and your plants grow beautifully or start showing deficiencies you've never seen before, then you're probably set for CO2.

-Philosophos

 

[_ReApEr]

Yep, 100% sure it's 4dKH, from GLF. And it's also 100% yellow. I'll plan on leaving it where it is for now, then, I'm sure it'll be a while before I can tell how well the plants are responding. Thus far, the plants are pearling, so that's a good sign I guess, even though they were before. The fish all seem perfectly happy so far, too. One concern I have is that pumping that much gas into the reactor causes a decent amount of buildup and it can be heard churning around in there for hours after the CO2 and lights turn off. Obviously, it's going to be spitting out CO2 for many hours after the CO2 stops, but I don't know if it's a problem. I do have surface agitation with one of my spray bar sections pointed upwards, which likely helps keep the water fairly oxygenated and the fish haven't shown any negative signs of night time CO2 yet. But the reason I'm still concerned is because I am still doing 50% water changes every day, after lights out to ensure the plants have their 8 hours to utilize the day's fertilizers. The water changes aerate the water like crazy. I don't know if Colorado water is typically like this or what, but here's a picture after refilling:

As you can see, there's a TON of air in there. So, I don't know if that's just giving the fish a good supply for the night or what, but I worry that when I stop doing the 50% water changes, the CO2 will start impacting the fish during the night. My CO2 reactor is, apparently, not very efficient. I was thinking of making a new one, but we'll see. I guess I could always try and remember to purge it at night. o.o;

Thanks.

 

[Philosophos]

Just run a timer on opposite cycles to kick on an air stone when the lights go out; should take care of your problem.

-Philosophos

 

[_ReApEr]

Tried that once already and it sprayed water all over the place from the bubbles bursting at the surface. Got my light all wet, got the stand all wet, etc etc. If I have to, I might try to find some way to make it work, but I'm trying to avoid that. I'll have to see how the fish act when I don't do 50% water changes.

Thanks.