Both Tanks Failing, Don't Know Why

[JackBinimbul]

Hey, everyone. I'm having issues with my tanks and I'm really hoping you guys could shed some insight on the problem.

Tank #1 is a 20 gallon community tank with two air-driven sponge filters on a 40 gallon pump. Had 6 corydoras, 8 endler's, 3 nerite snails and a bunch of neo. shrimp. For plants there is anacharis, java fern, java moss, pennywort, buce, and frogbit. It is moderate to heavily planted with black diamond substrate. Kept to ~76F with minor fluctuations between 75.5 and 79.5. I feed Hikari betta pellets, TetraMin tropical flakes, sinking wafers, frozen bloodworms and frozen brine shrimp both thawed in tank water. This tank is nearly two years old.

Tank #2 is a 10 gallon betta tank with neo. shrimp and two nerite snails. Has a marineland 15 gallon HOB filter with 1 marineland filter and the rest filled with lava rock. Planted with anacharis, pennywort, dwarf sword, and frogbit. Also moderate to heavily planted. Substrate is soil capped with pea gravel. Kept at ~78F with fluctuation between 76 and 81. This tank is almost a year old. I feed Hikari betta pellets, bloodworms and brine shrimp.

I have reduced my water changes in both tanks over about 4 months, but have kept doing tests. The plants were at just the right balance to have 0 ammonia, 0 nitrite and 0 nitrates. I would top off the tanks after testing every week and would still rinse the filters on schedule, rotating so I didn't rinse all of the media at the same time.

Tank #1 has had issues for about a month. My largest female cory started showing signs of illness by swimming sideways and struggling. She was quarantined and died within 24 hours. I did water tests and figured it must be a fluke. About a week after, another albino cory started showing the same symptoms and later died. On the albino cory I could look better for any external signs but saw none. No red spots, no bloating, no fuzzy spots, nothing. Just that they had both looked pale. I did a water change and removed some frogbit, in case it was preventing oxygenation. Started worrying that maybe I was underfeeding, so increased feeding. Couple days later, another cory had the same symptoms and lived a little longer in quarantine, but I think I had just caught it sooner. Did another, 50% water change and added salt to the tank. Yesterday, one of the endler's came down with symptoms. He is currently in quarantine and I will be euthanizing him tonight since he keeps getting worse. The shrimp seem completely fine and even had a recent boom.

Tank #2 I noticed yesterday morning during spot cleaning and topping off that the betta was looking a little plump. Decided to feed him a little less. Saw tonight that he is pineconing and staying at the bottom of the tank. Have drained the tank about 50% and added antibiotics to the water, but I don't have high hopes.

All of the tests on both tanks (ammonia, nitrites, nitrates, pH, kH, gh) are all great and have not fluctuated. These tanks are in different rooms and do not have any equipment or tools in common. What could be causing all of these issues??

 

[libertybelle]

I don’t have an answer but a couple things stand out that may need clarification. How long have you been leaving tanks with just topping up and when you do get around to water changing what percent do you do.

I likewise have had tanks with enough plants that nitrates don’t become a problem but I still do a water change when I need to top off to avoid accumulation of salts and any untested for contaminants. Could it be your tds is climbing high and then swinging back down stressing everyone out? Stress makes fish more susceptible to illness so stress could be what the tanks have in common even if it presents as different illnesses.

The other issue could be source water. Are you noticing the illness/symptoms cropping up after water changes or top ups? What dechlor. do you use? I started double dosing prime pretty regularly after my source water unexpectedly increased chloramines on me one week and killed off some fish before I figured it out.

 

[JackBinimbul]

Hey, Liberty, I'll clarify a bit. I used to do a 25% WC every week. Went to 50% every 2 weeks, then 25% every 2 weeks and for the last 4 months or so I have been doing every 2 or 3 weeks gravel/sand vacuuming and only replacing what I vacuum out and what has evaporated. So probably between 10-25%. Almost always 25-30% on the betta tank, since there's more evaporation.

My source water is just tap water. I tested the tap water today and the only difference was the tap had higher GH than my tanks. Now, obviously, there's things I can't test for.

I use API dechlorinator and have used the same bottle this whole time. I split the bottle into two containers tho, one for the community and one for the betta.

The problems don't seem to be following any pattern. The first one died right before I would have done maintenance where others died the same day or in the middle of the cycle.

I'm going to go back to actually doing scheduled water changes just to try to rule out tds or other build up that I can't test for, but I don't know if that will solve it.

 

[JackBinimbul]

Unfortunately, Mr. Bubbles the betta didn't make it through the night. I still don't know what caused his sudden bout of dropsy. I'll be maintaining the tank for the plants, shrimp and snails only, until I can figure out what happened.

 

[libertybelle]

Sorry to hear that.

Dropsy is more a symptom than a disease itself, as far as I understand it. The bugs that cause it are very common but generally don’t effect fish unless they’re stressed for some other reason.

How old was your betta?

A few weeks doesn’t seem long enough to cause major tds creep problems. From your original description I was thinking maybe we were talking months. Partial water changes usually can’t hurt (unless there is an issue with your source water of course) so until you figure out what the problem is going back to more regular changes is probably a good idea.

The fact that problems are developing in two separate tanks does suggest an issue with what they have in common. Source water and the chemicals / schedule that you use.

Could your test kits be old? Unless you are running co2 that is a lot of nitrogen for your plants to be using up so you never see it at all?

Edit: I just remembered your stocking is endlers and cories on the 20. Probably a pretty low bioload in both tanks which the plants could take care of. Have you had these fish since the tanks were set up?

 

[JackBinimbul]

The betta was only about a year old. He had colored up really nicely and seemed to be thriving. Even the night before he became symptomatic he was still jumping for food at mealtime. There have been no changes in his tank. No moving things around or anything like that. The only thing I changed was swapping out a new filter about a month ago. But I left all of the lava rocks unrinsed to properly colonize the new filter and did frequent testing.

I bought my test kit almost 2 years ago. Not sure how long it sat on a shelf, but it's the API kit. It seems to read true since I was using it to monitor my uncycled quarantine tank, too. I'm also not running CO2.

Both tanks have housed the same species without any new additions since they were cycled. The only addition to the 20 gallon was frogbit from the betta tank about 5 months ago to take care of an algae problem. The frogbit was rinsed and root trimmed before being added.

 

[libertybelle]

It sounds like you’re doing everything right. That’s not helpful I know!

If these were relatively new fish or old fish I’d be tempted to say well fish just die sometimes and you don’t always figure out why. But the fact that nothing major has seemed to change recently makes that tough. I’d still look with suspicion on your source water since you don’t have any control over what changes in that and it would be in common between both tanks.

You could try double dosing on the dechlor for a while in case there’s some increase in chloramines or heavy metals in the tap causing some chronic stress? It wouldn’t hurt and could cover a couple rare just in case scenarios.

I wish I could be more helpful; hopefully someone else will chime in with some suggestions.

 

[csuggett]

hi, i actually hired an aquarium consultant off Craigslist because i was having similar problems. They all but disappeared after i took his advice of only doing 10-15 percent water changes once a week...no matter what. (make sure you treat the water before you put it in the tank) Plus i was told to put my tanks at 78 degrees and get a digital thermometer so there aren't fluctuations. I stopped using salt, ensured my sponge was rinsed (in aquarium water!) once a month. So basically, once i started this regimen and rarely deviated then my lovely fish and plants are getting on much much better. Thanks.