IntrepidUT99

@Colu Thanks for the feedback and breakdown for a possible treatment! I unfortunately do not have maracyn2 on hand, would have to order. Would you happen to know if API Erythromycin can be used in its place?

@Colu Thanks for the feedback and breakdown for a possible treatment! I unfortunately do not have maracyn2 on hand, would have to order. Would you happen to know if API Erythromycin can be used in its place?

Background: Tank is a 20 gallon long, that has been up and running for close to two years now. Stocked with: Hillstream loaches, medaka rice fish and 100s of shrimp and snails. Heavily planted. As of three weeks ago I added 4 new juvenile medaka rice fish to bring the count up to 10. The current medaka population is 2+ years old, so nearing old age. A week after adding new fish, I did lose a senior Medaka. Today I noticed another of the older fish showing signs something is off. I am convinced I have something in my tank, however only signs of distress are with the rice fish. Looking at the medaka rice fish in question , it appears parts of it are "washed out" or losing color and some fins are not in the best shape. Its also swimming slower than the others. Current water parameters: pH 7.4 Ammonia 0ppm Nitrite 0ppm Nitrate 25 ppm Phosphate 0.5ppm GH 9 (~160ppm) KH 4 (~70ppm) Water Temperature 71 F Picture of the fish in question is attached.

@Seattle_Aquarist thank you for the amazing response. I did sneak in a response above yours right before you posted. I do have black brush algae in this tank that does like to remind me from time to time it exists. I had a bad explosion ~7 months ago due to attempting an iron supplement in the water, it was Aquarium Coop's Iron product. I wasn't aware of the differences in Iron uptake at different pH levels that is good information. My question is, would using Seachem Iron risk another battle with BBA and would iron based root tabs be a better method? Or am I off-base?

Thanks for responding @nabokovfan87! Some more background per your questions/feedback. Due to being on well water (Liquid rock with a side of arsenic), I use completely reverse osmosis water for my tanks which then I use only two products to get the water up to par. Salty Shrimp GH/KH+ which is basically just a water soluble powder of calcium, magnesium and bicarbonates in a fixed ratio for the GH and KH. The other product is Aquarium Coop's Easy Green Fertilizer for plants. Both products have a listing of their contents, not sure if this helps narrow down if anything is building up in the tank. I also have non-API test strips to check for spikes in Iron, Lead, Phosphate, Copper, and Zinc. Granted test strip accuracy can vary, but the test strips come back in nominal ranges for Iron, Zinc and Phosphate and negative for the rest. I am hesitant to dose increased iron into the water column as this tank does have black brush algae, I've won the long battle with it, but it loves to come out and wave at me through the tank if things go out of balance. Iron levels in particular. Is there Iron only root tabs that would work instead? No issues temporarily going back to weekly water changes as an experiment with this tank, the head scratcher is some of my other tanks are currently on similar water change schedules of 3-4 months and the rotala in those tanks grows almost out the water a week or so after trimmings. If the water change works and nothing stands out in terms of build up, my uneducated opinion goes toward some sort of allelopathic conflict between the rotala and another plant in the tank. I am aware hornwort and dwarf sagittaria can do this to tanks if they are able to take over a majority of the tank, which is why I limit their growth. The one plant I am not too sure on is susswassertang. I have it in all my tanks, but this tank its by far the most successful in growth speed. I am not sure if any information exists on if the plant releases chemicals that can lead to allelopathy? 🤔 On the root tab front, I used Aquarium Coop's root tabs as a test. Usually for my planted tanks, I just use old substrate containing rich amounts of mulm/detritus from previous well established tanks I've rebuilt or torn down as a base layer in the new tanks that I cap with new substrate. It's my free aqua soil equivalent and why the amazon sword in the tank took over so quick 😅. To keep it going afterwards, I throw in pest snails such as trumpet snails.

I have a 20 gallon long that has been up and running for a little over a year now. In July of this year I decided to do some rescaping in the back and removed the original background stem plants and replaced them with some rotala indica clippings. These clippings are from my other tanks where even if I tried to kill it, the rotala grows like a weed. However upon planting it in July, it honestly hasn't done much up to the present. Its branched out from the initial clippings I placed but it stalls as it attempts to grow upward. Just stops growing then algae slowly settles in. I clip the algae stems away, it regrows, stalls and repeats. I usually never use root tabs, but I gave in and tried those as well. That was 3 weeks ago, and I have yet to see much difference. At this point, I assume something is missing in this tank that the other tanks of mine have, but I am at a loss as all my tanks use the same substrate (inert sand and gravel) and water is the exact same parameters each water change between all tanks since I re-mineralize it myself. I haven't noticed any other plant struggling in the tank, outside of the occasional old growth dying off of established plants. Other stem plants in the tank I trim monthly. I've also thrown an image up of the tank as well to this post. I suppose my questions are, what may be causing the rotala indica to struggle? If its not missing nutrients, is it due to another plant competing with it? Background on tank: Tank routine: 10% water change every 3-4 months with reverse osmosis water that has been re-mineralized with salty shrimp GH/KH+. Top offs are with reverse osmosis water only once a week or as needed. Easy Green fertilizer is used once a week, and fish are fed every other day. The lights are on 70% power and are on for 8 hours daily. Water Parameters never really change in this tank, here are the results of testing prior to this post: Ammonia (NH3): 0ppm Nitrite (NO2): 0ppm Nitrate (NO3): 10-15ppm General Hardness (dGH): 9 Carbonate Hardness (dKH): 4 pH: ~7.4 Other plants in tank: Azolla (Floater) Red root floaters (Floater) Water Lettuce (Floater) Hornwort (Floater) 1x Amazon Sword (root plant) Dwarf sagittaria (root plant) Ludwigia sp. White (root plant) Ludwigia green (root plant) Susswassertang Various Buce clippings from other tanks Various Anubias clippings from other tanks I think I've killed this post with data, if anything is missing let me know. 😅