I have a heavily planted 6.6 gallon (bookshelf) with one betta and two otos (I had previously posted "pygmy cories" but I was mistaken... another long story... I know otos are probably not the best choice for a 6.6g but I've been feeding these two Rapashy soilent green and they are THRIVING and FAT...)
Anyway. The tank is cycled. It has a filter, running with fairly low flow so as not to bother the betta. I do weekly 50% water changes and sometimes one extra if I notice anything funny on the water test.
Suddenly, I am having a cyanobacteria problem! I went away for 3 days last weekend and my mother overfed the soilent green, I think that may have caused the problem. I came home to a blanket of blue-green covering a LOT of the tank substrate and the plants!
In steps to address possible problems, I have:
- cut the feeding of soilent green back
- manually cleaned out all cyano growth every day
- done 25% water changes every 2nd day
- run the lights 8 hours a day instead of 10
- turned the filter up from a "bare trickle" to a little more
- gotten more regular with my daily dose of Seachem Excel (I was previously pretty lazy about it)
- bought Seachem Nitrogen & dosing at EI levels daily. I know very little about plant fertilizers. I got into the live plants thinking that they live on the fish waste, so actually adding extra stuff to the tank for them plants did not cross my mind. Now I am learning that perhaps I need to research this a little more. I read in several places that a lack of nitrates can cause cyano. My nitrates have always been very low (0 or close) which I attributed to the plants using it up.
Things are looking better in the tank after those steps. However, every day at least one little patch of cyano grows in the substrate (eco-complete) by the front glass. It's very hard to get that out of the substrate. I've been scooping it out and manually cleaning it but it's hard to get it all.
Just wondering if anybody has any advice for me. Am I on the right track? Is there anything else I should be doing?
A big question is, should I turn up the filter even more? I know my betta would not like it, but I keep reading that water movement is important. Would an airstone help? I don't have one. I've heard it's a myth that they increase oxygen in the water, but I'm sure it would help with water movement. Because the bookshelf aquarium is long and the filter is on one side, the other side is quite stagnant. I liked this about it previously, since Sparkie the betta likes still water, and he builds big bubble nests over in that quiet corner of the tank. Strangely, the cyanobacteria grew all over the tank, and does not seem to be favoring the stagnant side.
My biggest issue right now is that on Sunday (2 days from now) I am going away on a one week cruise. My mother is enlisted to care for the fish again. I have set her straight on the feeding schedule, and I think I can ask her to continue the Excel and Nitrogen dosing. However, I don't think I can ask her to do more than that. I planned to do a water change right before leaving and immediately upon return, and previously my tank has been fine with weekly water changes so I wasn't worried. Now I'm really worried that I'm going to come home to a major cyano outbreak. I really don't think I can ask my mom to do water changes. So, is there anything I can do to minimize the cyano growth while I'm gone, other than what I'm planning? Should I turn off the lights completely for the week or reduce them even more? Any other ideas?
When I get back I will be able to tackle this with a vengeance including blackouts or antibiotics if needed - hopefully not, though.
Thanks for any advice.