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New Hobbyist, Tank, and Cyanobacteria

1208 Views 6 Replies 5 Participants Last post by  zahtar
I'll preface by saying my tank is a 5 gallon tank about 2 months new. It's been populated by a few ghost shrimp and a nerite snail. I'll also add that I am incredibly new to this, and don't yet have have a lot of the experience, money, or consistency required for this hobby. You'll see all of this in action momentarily. I apologize in advance for the long read, but figured the more info I include, the easier it will be to diagnose my problems.

For the first month of my tank's cycled life, the NO3 tested consistently at 0ppm. I recently started a regiment of liquid nitrate/fertilizer supplementation. I have a goal of 10ppmNO3, but I haven't perfected my dosing schedule yet.

I'm also poor and, as a college student, have almost no sleep schedule to speak of. The lighting period on the tank ranges from 8-15 hours per day, depending on when I am home to turn the lamp on/off. Currently the tank sits below a 4w LED desk lamp. A few of my plants have high lighting requirements so I tried to make up for lack of intensity by increasing the photoperiod. This did make the plants a little happier, but from my vague understanding of CO2, the levels probably fluctuate a lot more than they need to. I do not run a CO2 system, but I dose the tank with API's liquid CO2 before I turn the lights on in the morning.

I also set up the tank without considering waterflow. I had a sponge filter set up behind a piece of driftwood in an alcove behind sloped substrate. It looked awesome, aesthetically, but the only real water circulation was happening in that one back corner. The kitty corner of the tank had almost no water flow, as did the portion in front of the driftwood. All of those portions are part of an unplanted sand path, as well, which means they received uninhibited exposure to my lamp light.

So what happens when inconsistent CO2, a long photoperiod, poor water circulation, and low nitrates all happen at once? Apparently cyanobacteria! Luckily I noticed it before it overtook anything. I had 3 spots of my sand about 1 square inch each and a baby plant growing a lovely blue-green slime. Gross.

I overhauled my filter system and improved the water flow, vacuumed/peeled up as much of the CB as I could, removed the plant, blacked out the tank for a few days, and turned off the heater. As soon as I turned the lights on again, though, the CB came back in all its slimy glory. After a week of fighting, I went a little nuclear. Removed the filter/sponge, squirted some H2O2 directly on the affected areas, waited 12 hours, vacuumed up the newly-dead slime, and put the filter back in. So far, it seems to have worked like a charm. No new ammonia after 24 hours, either, so I don't think I killed my biofilter with the H2O2. Score.

If you've read this far, thanks for sticking with me. I've researched as much as I can on my own, but think it's time for advice from the experts. Here are my questions.
1: What level of NO2 should I aim for in my aquarium? I don't ever want to exceed 20ppm because I want to keep a neocaridina colony in there once I stabilize everything, but I also don't know if keeping it at/below 10ppm is asking for another cyanobacteria bloom.
2: How can I improve water circulation in such a small tank? I've read that I'm looking for a flow rate of about 20gph, but all the pumps and powerheads I've looked into run in the 90+ range. I'm hesitant to buy a bulky submersible filter or a HOB filter because my tank is so small, but I'm considering that option if my ratchet pump solution fails.
3: Should I still dose my liquid CO2 every morning? Could that be a contributing factor to cyanobacteria?
4: Should I aim for longer photoperiods of my low intensity light, or should I try to keep it shorter?

Thanks in advance for anything you have to say. Feel free to roast me and my inexperience, too. The extra shame might help me get my crap together.

Edit:
Parameters at the moment are
0ppm ammonia
0ppm nitrite
7ppm nitrate
11GH
7KH
7.2PH
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I'm a newbie too but I'm in the same boat so I'm just leaving a comment to bump this post so hopefully I can learn too.
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Get a cheap timer from the hardware store or grocery store and plug your light into it. Set for 7 hours. You can get a higher watt LED bulb too like 20watts or something. The liquid carbon help kills algae too. Some people have magic water and you might not need to add liquid carbon.
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I'll second getting a cheap timer so your photo period is consistent. Sounds like you are going for a low tech planted shrimp tank? As long as you do weekly water changes 50%, I wouldn't worry too much about your nitrates. They likely aren't directly causing the cyanobacteria and many folks with planted tanks keep them a little higher on purpose. Adding phosphate or oxygen to the tank will both hinder/prevent the future development of cyanobacteria (as will the liquid CO2/Excel/Glutaraldehyde).

Sounds like you're running a sponge filter, so the water should be fairly well oxygenated. If you want more flow, see if you can run your sponge filter using a jet-lifter from swiss tropicals:


They actually move a lot more water around the tank than the standard vertical bubble tube most sponge filters have. If it won't fit your current filter, you can just suction cup the jetlifter in the tank to move water around. Or just buy a small sponge filter from swiss tropicals and run it in parallel with your existing filter for a month if you don't want extra stuff in your tank all the time and don't want to fiddle with matting up filter parts.
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I'll second getting a cheap timer so your photo period is consistent. Sounds like you are going for a low tech planted shrimp tank? As long as you do weekly water changes 50%, I wouldn't worry too much about your nitrates. They likely aren't directly causing the cyanobacteria and many folks with planted tanks keep them a little higher on purpose. Adding phosphate or oxygen to the tank will both hinder/prevent the future development of cyanobacteria (as will the liquid CO2/Excel/Glutaraldehyde).

Sounds like you're running a sponge filter, so the water should be fairly well oxygenated. If you want more flow, see if you can run your sponge filter using a jet-lifter from swiss tropicals:


They actually move a lot more water around the tank than the standard vertical bubble tube most sponge filters have. If it won't fit your current filter, you can just suction cup the jetlifter in the tank to move water around. Or just buy a small sponge filter from swiss tropicals and run it in parallel with your existing filter for a month if you don't want extra stuff in your tank all the time and don't want to fiddle with matting up filter parts.
I ended up buying a timer and have it running 5 hrs on, 4 off, and 5 on every day. I also took the sponge filter out and replaced it with an 80gph fountain filter. The tank is so small, though, that even that baby pump. overwhelms it with flow! I ended up stuffing it with a sponge to decrease the flow and attaching a little acrylic spout so it spits the water out above the waterline. It seems to stay pretty oxygenated, and my parameters seem alright still (the sponge i stuffed in came from my old cycled filter).

Unfortunately, I lost all my shrimp but one. I didn't catch any ammonia or nitrite spikes, and my nitrates are consistent too. It may have more to do with an unrelated GH travesty.... or the fact that they were ghost shrimp from petsmart...
The cyanobacteria is gone, though! Thank you for your advice!

I might end up breaking down the tank and setting up something a little more friendly for a new shrimp colony. My substrate is completely inert and I didn't add root tabs when I started (noob) so the plants are already showing signs of deficiency. I think the complete lack of nitrates i had was causing a lot of my problems, coupled with the poor flow.

Cyanobacteria is vanquished, but I want to change the tank anyway... I'll be back for more advice soon im sure
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Get a cheap timer from the hardware store or grocery store and plug your light into it. Set for 7 hours. You can get a higher watt LED bulb too like 20watts or something. The liquid carbon help kills algae too. Some people have magic water and you might not need to add liquid carbon.
I grabbed a timer and updated my filter for more flow. I have a new light, too, with a 20 watt led bulb for it. I haven't set it up yet because I think im going to do a full re-scape to fix unrelated problems in my substrate... but the timer worked like magic! I think I can confidently say the cyanobacteria has been vanquished. I think I learned a couple important lessons and hopefully my next try will work out better.
My first tank was similar to yours, and I had problems growing some plants (namely floating plants). Similar to you, I thought that the problem was not enough light, but the real problem was that the tank was not balanced.

There are three things that you need to have in balance:
a) light,
b) CO2 and
c) nutrients.
If one is way off, algae may develop a lot. If the three are relatively balanced, algae will stay to a level you can tolerate, maybe hardly noticeable. Totally avoiding algae is a hard thing so you may consider it a part of your ecosystem.

Regarding light, I believe that less light is needed in some cases. You can start from tropica's guideline, that is 10-20lumen/litre for easy plants, 20-40 for medium and 40+ for difficult. Of course medium and difficult plants mean an increased need for CO2 and fertilizers (don't forget the balance mentioned above). Having no injected CO2 and no scheduled scheme of fertilization means you probably won't be able to grow difficult plans. That's a good thing because such a setup is expensive and needs a lot of your spare time. I'd go with easy plants, like anubias, microsorum mini or windelov, limnophilla sessiliflora, bacopa compact, marimo, salvinia natans (aka salvinia auriculata) and cryptocorynes. I'd buy a smart RGBW bulb for the desk lamp which would give me the ability to regulate light intensity and color temperature to my taste. In combination with a timer that would provide with total control over light.

I have been successful with the above in a 16lite (approx 4gal) NPT (Natural Planted Tank) also known as Walstad tank. You can check the El Natural subforum for more information.

Have fun!

Reference:
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