Thanks! I would still stick to 50% wcs every 3-4 days as 150l is just under 40g. It really does wonders for fish health and growth.
In respect to treatment, you will need to do wcs every other to daily along with good gravel vacs. This will help to remove ich (along with salt) and may be necessary as salt can upset your good bacteria resulting in toxin spikes. If your bacteria are affected, the good news is they recover quickly once the salinity is reduced to normal tap levels.
Based on a 40g tank, you will need to dissolve 11.4grams of appropriate salt per gallon (or
approximately 2.5 level teaspoons per gallon) into a container of conditioned water. Weight is a much more accurate means of measurement for salt as different grain sizes will weigh different amounts and have different volumes (kitchen scales work great for this purpose). Once the salt is fully dissolved into solution, do a decent wc then start to add the salt solution gradually over the next 48hrs. Half should be in the tank at the 24hr mark, next half over the next 24hrs.
Then you will just need to maintain the .3% salinity level for one full week to ten days AFTER the last spot is gone. Wcs should be done frequently. When doing a wc, you only want to replace the salt you remove. So, for example a 50% wc, dissolve half of the total amount of salt you originally added into solution and add this solution along with the new water. Once treatment is over, simply return to normal wc schedule and do not add back salt with future wcs. That's about it! Treatment typically takes about two weeks but in more difficult cases, it may be a bit longer. Please ask if you have questions!!
