Early Flower Humidity Issues... How to Lower RH Without Increasing Electricity Costs?

A.i. sayz just crack da tent open for 10 minutes every 5 hours to vent humidity. BeeecuZ plants do sweat reduce watering, or eliminate an entire pha$e of watering. Did I Say ai, I joke 🏂

I guess in short if you are not running your lights at nighttime that will help balance the environment out. Also electricity is cheaper then my flower tents run from 8pm to 8am. That's off peak hours and allows me to get into my tent in to morning or nighttime.

I like this format you posted your question. This seems like a good use of ai. nothing weird or off. I been opening my window in basement going into fall/winter at actual nighttime when I run my lights and its coolers and less humid out. Because I'm using my lights full bore to help keep the humidity in check. but recently been hitting almost 32 C when lights on. so that's why I'm bringing in cold dry air, helping a ton. The colder you get though the less moisture the air can hold which will make the relative humidity faster quicker. Don't do it if its super humid outside. The humidity usually dissipates during the daytime when lights are off in my tents and naturally warmer. i do run a dehumidifier in lung room as needed but you said you don't want to do that. I agree your humidity is not that bad. and I also experience high humidity the days i water. Mulching your top will help with evaporation loss and humidity spike that way. try to go and extra day between watering. or simple rasing you lung room temperature will increase the amount of water the air can hold, and the relative humidity will naturally decrees with higher temps you can go up to 23.8 C if you want to. may reduce the amount of color expression you get if that's desirable for you.

Gas exchange may or may not help and dehum or heating the air isn't cheap... No way around it.... You can either run a dehumidifier or you can raise temperatures during lights-off -- common sense necessary for the latter option... May not be viable in all situations, but a dehum will be efffective in any context. Buy larger than you need and it'll last longer. If it runs hard all the time, it'll die in a few years. They all have auto-defrost/safety features to prevent damage, but best not to rely on those features all the time if you care about longevity. Gas exchange with outside air (extraction) might help. You must account for temperature change and any effect on inside temperature while doing so, and that will tell you if gas exchange can be effective. e.g if it is 50F and 90% RH outside, if that air warms up to 75F inside your home, the RH drops to roughly 37%. That air would help lower RH. You can google for a RH conversion due to temperature change for easy reference. If it were 70F inside that 50/90% converts to ~ 70F / 45%, or therebouts. That would still hep but not as effective (more gas exchange needed). As long as it's equal or lower RH once it warms up, outside air can help. Obviously, the drier it is by comparison to target RH, the more effective it'll be. That's definitely teh cheapest route, but may or may not be enough. Also, variables in late flower with a fully grown canopy will be much more demanding. So, it might be enough early on but not sufficient later... just depends. ------------------- details, if interested 80x80 canopy shouldn't need anything too beefy unless you also contend with high ambient RH to start. I'd still get a 50pt/day AHAM rated dehum. ~200 USD, probably. Probably more than you need, but it'll last longer and cost of operation will be cheaper in long-run. As far as efficacy of a dehum... that information is often not provided. Must dive deeper or pester customer service for information. The higher end units are as high as 2.1L/kw-hour last I looked -- Doubt they've improved much the last 3 years. Dehums are an excellent example of bullshit marketing.. the pints per day ratings depends on temp/RH conditions... so 'at saturation' it's about double or a bit more than double what you can actually expect at typical operating conditions. e.g. a 150pt/day at saturation becomes 70pt/day at more rational temp/rh conditions. Important when comparison shopping to make sure you are comparing apples to apples. AHAM = average heat and moistuer or something to that effect.. think it's 60F/60%, but don't quote me on that.. google can fill in that blank. It doesn't take much change in temp to have a significant impact on RH (*effect is not linear) If it's spiking to 70% now, it'll be even higher once that canopy is fully grown. Larger canopy = greater rate of moisture released into air. keep it under 65% ... a spike for a few minutes probably isn't a concern as long as a "spike" isn't near dewpoint (in other words, no condensation occurring), but daily occurence is a concern... if growing photoperiods, a wireless temp/rh probe is helpful to avoid interrupting dark cycle. A few years ago i thought i was contorlling RH, but once i had a wireless probe, i realized RH was spiking after lights out to dangerous levels starting around week 5 of flower phase... canopy full grown and temps dropping significantly... bad combo. End up with a mold factory.

I would get a green house tube heater, cheap to run and buy really,, with thermostat..

Heat is effective and cheaper then dehumidifier (I guess?!). If you buy a cheap dehumidifier the effect of the heat is probably higher than the actual dehumidification 😅 Campfire is probably the cheapest .. but only if you don't have a filter 😛 You could also make the air inlet a bit larger, but not too large I think there should be a little direct air flow. Another option is insulation, especially at the bottom and sides of your box to keep the heat after lights off longer (also prevent condensation on the side of your box (really had that!) It's better to have your lights running at night. Usually it's colder.. higher RH. Best option IMO do it like me and just ignore stuff you can't control 😅 Just be sure to have a good air circulation inside your box to prevent mold. just in case.. 5% are like nothing. You could even place your probe somewhere else and you are perhaps already in the right spot ;-)