Hi cody94549, Most TG'er simply let it rain... Then again, it really depends on the amount of rain that infiltrates the TG internals. You can mitigate nutrient solution dilution by plugging unused growing ports. You should also 1) Perform regular, complete nutrient tub changes every 30-60 days. 2) Top-off nutrient solution with a fresh mix when the tub solution level drops 5-gallons (and never let it drop more than 1/2 full: 10-gallons). If you notice that a heaver than normal rain storm has substantially added to the level of your nutrient tub, then use the clear hose that came with your TG and drain about 5-gallons off... then refill with a fresh mix. Keeping in mind this is simply a band-aid. Without using a EC/TDS meter and getting a lot more complicated, there isn't much more you can do here to re-balance your nutrient solution mix.