Saying this will probably get me attacked... but I don't know why anyone does not carbon dose now. Not like the dosage rates to bring down nitrate issues, but even just a few ml of vinegar a day. Boosting the bottom of the food chain while not increasing but actually decreasing phosphate and nitrate as a byproduct, a rare win-win. I even dosed a little vinegar with kalk in my biocube without a skimmer and it did great. I always try to remind people that carbon dosing is not just for nutrient export. The exception may be seahorse tanks. I do not know what effect this would have on them, but it would be cool for someone to explore. It might be horrible for them and bacterial infections, but it's also possible that seahorse pathogens are out-competed or just don't grow (to higher levels) with carbon in the water. I don't think anyone has determined that yet.