2 deaths and brown algae - next steps?

[MissJay]

Hello! I have a 30 gallon planted aquarium with 8 harlequin rasboras (two died last night), 6 bronze cory cats, and 2 nerite snails. The tank was cycled for 2 months before adding fish, and i have added fish slowly over the past ~6 weeks. I do 30% water changes every week and test the water twice a week.

Current specs: 76°F, pH: 7.2, Ammonia: 0.25ppm, Nitrite: 0ppm, Nitrate: 20ppm. I have a Fluval 50 AquaClear HOB filter and an air pump.

4 days ago, the Ammonia was 0 and the Nitrate was 5ppm. I just did an 80% water change, rinsed my filter materials in tank water, scrubbed algae off my driftwood, and wiped down the glass. I suspect the Ammonia is what killed my two fish.

All of my other fish appear to be fine - full of color, swimming, eating. The two dead rasboras had lost all color and were the youngest of the school. One was bloated near the filter and the other was shrunken, sunk to the bottom of the tank. These two fish must have died some time in the night, as I fed them and did a count before going to bed.

My problems: I don't know where this ammonia spike came from (could be from over feeding, but I'm pretty good at cleaning whatever they don't eat). There are many particles in the water and the water is more brown than it was ~4 days ago. Many of my plants (Pennywort, Lloydiella, Hornwort) are turning brown and being covered with brown algae. I can rub the brown spots off the stem plants, but not the Hornwort.

So, I'm not sure what I should do next... I've limited the photoperiod to 6 hours and rinsed off most plants. Should I buy something to eat this brown algae?? Some shrimp?

Pictures provided:
https://imgur.com/VXkNnnn
https://imgur.com/LDUWVRD
https://imgur.com/a/8kMozrz
https://imgur.com/fi43l4U

 

[Reygan2]

Check your tap water for ammonia.

Likely you have a diatom bloom, which is normal in newer setups. It should clear up over time. You could always get a few more nerites to help clean up. Your brownish water could be from tannins leaching from your driftwood. What type of lighting do you have? I´d suggest increasing the amount of water you change per week to at least 50%. I don´t think you´re overstocked, but you need to get that ammonia to zero asap. Check your tap water and we´ll go from there.

 

[V227]

^^^^^^ +1 ^^^^^^
My only other suggestion would be to add one Bristlenose Pleco. Mine are algae eating machines. The Bristlenose won't outgrow your tank.

 

[Angellove78]

Less lighting for the algae. Ammonia spike is most liking from all the newer fish. The more fish you have the more waste is produced. Some fish get stressed in New tanks, and different fish. Specially if lights are on when introducing, or lights on the same day of adoption. Brown water is from your driftwood. And sounds like you've done everything you can for now. Just test your water and keep an eye on them. Keep the bottom vacuumed. Be careful with big water changes. Get some Otto cats. They stay small and you'll love them. They do a good job. I'd get about 4 for your tank. They will clean the plants and glass very Well!

 

[MissJay]

Thank you for replying! the ammonia, nitrite and nitrate in my tap water is 0ppm. the pH is 8 (I let tap water sit out and 'age' for a day before adding it to my tank). After my last water change, the ammonia is back to 0. I've also gone to feeding them only one a day. I will do 50% water changes weekly and keep testing the levels every couple of days.

My lighting is a single, regular CFL in a standing office lamp. so, not much lighting. My plants do seem to be doing a little better after the water change.

 

[MissJay]

i've heard lots of good thing about Plecos, but I love my driftwood and don't want it to get eaten away :/

 

[MissJay]

Yea, I guessed the new fish might have been the culprit. But I added them like... 2 weeks ago. And I added them slowly, first just 4 rasboras, wait a week, add 6 more, wait a week, add 6 cory cats.

I have a regular, non-python suction column and it just... doesn't suck up all that much. Does a python have better suction? I've heard people saying they use turkey basters too.

I will probably get some Otto cats! They sound very helpful and they'll get along with my other catfish. Thank you very much.