Bacterial bloom with Maracyn treatment in high Ph / Hard water tank

[Eric R]

So I have had 7 Paracyprichromis nigripinnis (Blue neon herring cichlid) in a tank by themselves for about 6 weeks. I had no deaths for the first 4 weeks (except one a few days after they arrived, I don't think it handled the overnight shipping well - I ordered 8 and it was pale and lethargic compared to the others). Then I had one die with no symptoms, parameters were all perfect (0 amm. 0 nitr. 5-10 nitr. dkh 14 dgh 18 ph 8.0 temp 77), then another several days later, still no symptoms. So I decided to treat with Maracyn and ParaCleanse, per Aquarium Coop treatment suggestions on Wednesday, after vacuuming the tank and doing a water change. I haven't fed since then, and I noticed a bacterial bloom this evening. Tested parameters, sure enough I had detectable nitrite (0 amm. 0.25 nitr. 10 nitr. dkh 14 dgh 18 ph 8.0 temp 77). So I did a 70% water change, being sure to match the parameters before changing.

I find this interesting, as @Bill Smith mentioned in a post that he always has bacterial blooms after a Maracyn treatment. I add baking soda and epsom salt to my tap for this tank, since its a Tanganyikan tank. Bill's thought that he gets bacteria blooms while Aquarium Coop didn't in their testing was due to his water hardness. Curious if that could be the case here, since I have such hard water in this tank?

I'm also currently treating a 5.5 gallon tank with a group of 9 juvenile white clouds that I just purchased, I haven't yet had a bloom in that tank, but it just has water from my tap, which is sourced from our well (7.4 ph, 4 dkh, 7 dgh). I also am treating that one prophylactically with Ich-X, which I'm not doing is this tank, since none of the fish have shown signs of Ich. I am planning to follow the current treatment with a course of Ich-X for this tank, I was just spacing them out since the Paracyps seem to be more sensitive.

 

Edited May 8, 2021 by ererer

[Isaac M]

That is interesting, I have no idea what the answer is but this would be a great thing to clear up for anyone with hard water using Maracyn in the future. Thank you for bringing this up, I will be following this closely to learn more. 

[Eric R]

So I woke up this morning to another bloom. No detectable ammonia or nitrite levels at this point, so I'm just going to continue monitoring. I may add some marine salt mix to the tank, since apparently it helps to reduce nitrite toxicity (along with elevated calcium levels)  https://www.practicalfishkeeping.co.uk/features/frequently-asked-questions-on-nitrite/ If my calculations are correct, ~1/8 of a tsp of salt per 10 gallons should be enough to reduce the toxicity of 1ppm of nitrite.

[Copied and pasted from above link]

What can I add to make nitrite less toxic to the fish?

Aquarium salt (sodium chloride) has long been used as an aid to reducing the toxicity of nitrite, because it has been shown to prevent methaemoglobinemia under certain conditions.

Some fishkeepers don't like using salt, but in my experience, when used at the correct dosage, it's never caused problems for any fish, even stereotypically salt-intolerant species. A fairly low level of salt can have a significant effect on reducing the toxicity of nitrite, so you don't need to add very much.

Research suggests a 10:1 dose (just 10mg/l of salt per 1mg/l nitrite) is effective for most freshwater species. The addition of salt for controlling disease or osmoregulatory problems does need higher doses!

Why does adding salt help?

The addition of salt provides chloride which reduces both the methaemoglobinemia and the toxicity of nitrite in the blood. However, interestingly, although the chloride has always been provided via sodium chloride, more recent research suggests that calcium chloride can work as well, if not better, because the additional calcium is also thought to decrease gill permeability, which prevents as much nitrite entering the blood.

For this reason, fishes kept in water with a higher calcium and chloride level, are usually less sensitive to nitrite than those in freshwater with a low chloride and calcium concentration - but many marines remain sensitive.

Theoretically, fish kept in warm, soft water (ie. Discus) are most at risk, but nitrite can and does kill fish in all water conditions.

[Eric R]

Also, here's an interesting discussion on whether Prime (or any or the related water conditioners/ammonia detoxifiers, like Amquel Plus) can detoxify nitrite and nitrate as well as ammonia. [I don't know how to paste just the link without it showing the whole first post. Click on the post to take you to the whole thread].

 

Edited May 8, 2021 by ererer

[laritheloud]

10 hours ago, ererer said:

So I have had 7 Paracyprichromis nigripinnis (Blue neon herring cichlid) in a tank by themselves for about 6 weeks. I had no deaths for the first 4 weeks (except one a few days after they arrived, I don't think it handled the overnight shipping well - I ordered 8 and it was pale and lethargic compared to the others). Then I had one die with no symptoms, parameters were all perfect (0 amm. 0 nitr. 5-10 nitr. dkh 14 dgh 18 ph 8.0 temp 77), then another several days later, still no symptoms. So I decided to treat with Maracyn and ParaCleanse, per Aquarium Coop treatment suggestions on Wednesday, after vacuuming the tank and doing a water change. I haven't fed since then, and I noticed a bacterial bloom this evening. Tested parameters, sure enough I had detectable nitrite (0 amm. 0.25 nitr. 10 nitr. dkh 14 dgh 18 ph 8.0 temp 77). So I did a 70% water change, being sure to match the parameters before changing.

I find this interesting, as @Bill Smith mentioned in a post that he always has bacterial blooms after a Maracyn treatment. I add baking soda and epsom salt to my tap for this tank, since its a Tanganyikan tank. Bill's thought that he gets bacteria blooms while Aquarium Coop didn't in their testing was due to his water hardness. Curious if that could be the case here, since I have such hard water in this tank?

I'm also currently treating a 5.5 gallon tank with a group of 9 juvenile white clouds that I just purchased, I haven't yet had a bloom in that tank, but it just has water from my tap, which is sourced from our well (7.4 ph, 4 dkh, 7 dgh). I also am treating that one prophylactically with Ich-X, which I'm not doing is this tank, since none of the fish have shown signs of Ich. I am planning to follow the current treatment with a course of Ich-X for this tank, I was just spacing them out since the Paracyps seem to be more sensitive.

 

I treated my tank with a round of Maracyn a few weeks ago and did get a bacterial bloom at the end of treatment. Mine was a bit different from yours. My nitrite-consuming bacteria appeared to stay intact, while the ammonia-consuming bacteria was reduced.

I have moderately hard water and a high pH without CO2 (pH 8.0-8.2, amm 0, nit 0, nitrates 5-10ppm, 10 dkH, 10 dgH) and had to go through a mini-cycle after maracyn. I never really saw nitrites elevate to a measurable degree, though!

Edited May 8, 2021 by laritheloud

[Eric R]

So just an update. The bacteria bloom cleared up after a couple days, never ended up with detectable nitrite or ammonia the second time. I did snap a picture of the second bacteria bloom, and the other tank I was treating with the med trio that didn't get the bloom for comparison.