OK I think I understand now. A tank with only a massive sump of pothos may be ideal. In a biofilter- potho combo after adding the pothos, as they grow they slowly steal more and more ammonia away from the BB in the biofilter. Which lessons available bb in the filter, but also lowers nitrates. Because the biofilter generally only converts ammonia to nitrite then nitrate, while pothos absorb it. So, if you had a situation where the pothos were to all die and start rotting you may have an ammonia super spike since they are now taking the load.
Tell me I've got it now?
Yes. There were no studies that I found that used pothos, so while I can tell you that potatoes, melons and roses were tested and found to prefer ammonia first, I can't say Pothos does that for certain. I'd be concerned that the pothos were reducing (not eliminating) BB by competing for ammonia, so in the case where plants were suddenly removed, I'd want to reduce feeding and act as if a large amount of BB had been removed, since the existing population would have been sustained on less than the full ammonia generated in the tank. Give the tank a week and slowly increase food while taking readings. The BB in a week will have increased 100 fold and things will be fine.
enjoy!
