You’re very welcome, sir – if the information regarding the formalin was too late to help in your case, at least it’s posted on the discussion forum now and will hopefully be able to help other hobbyists seahorses in the future.
The excited “trumpeting” behavior you observed from your stallion when he was reunited with the female is a courtship display, more specifically an invitation and a prelude to the copulatory rise and exchange of eggs. It seems that absence only makes the heart ponder in the case of our amazing aquatic equines, and that your stud is ready to consummate their pair bond immediately. Having a healthy interest in courtship and breeding is always a good sign, sir, so hopefully things are looking up.
If the ammonia spike was not pronounced or prolonged, and you detected it early and added more nitrifying bacteria as soon as possible, then I don’t think it should have any further deleterious affects on the seahorses. If they are interested in mating at this time, and your ammonia, nitrite, and nitrate levels are all back to normal again, and optimum water quality has been restored, I think the ponies should be fine despite the transitory ammonia spike.
I always like to keep SeaChem Stability on hand so that I can add a dose of it following every partial water change, whenever I have used any medications in the aquarium, whenever there is a blip in the ammonia or nitrite levels, as well as using it routinely for monthly “boosters” to assure that the biofiltration is operating at maximum efficiency at all times. The Stability by SeaChem includes not only beneficial nitrifying bacteria that convert ammonia and nitrites and then reduce the nitrates to nitrates, but also has denitrifying bacteria that complete the nitrogen cycle by converting nitrates to nitrogen gas, as well as facultative bacteria that help to break down detritus and any other gunk of organic origin that accumulates in the substrate or filter media, and is therefore extremely useful for helping to maintain optimum water quality at all times
Best wishes with all your fishes, Kris!
Pete Giwojna, Ocean Rider Tech Support