Input needed from a experienced RDWC/UC grower

Hello, I'm new to the Forum but would like to thank those who take the time to post helpful info.

Looking for a little help from an experienced grower on a Setup I'll be building in the near future. It's a Under Current system in a 8'x4'x8' tent (considering 8'x8'x8'). I'm new to this type of growing so any suggestions to help improve the overall design/efficiency, would be much appreciated. I've attached a Picture below of what I got sketched out so far. I will be adding in some dimensions and fittings to the drawing later (for expansion, breakdown).

The 8×4x8 tent will be in a 20' x 20' basement that typically stays 10-15 degrees cooler than the outside temp in the summer. It's not a true basement 3 of the walls are 8' underground and 1 is ground level, due to the house being built into a hill. However, it's always humid down there with some mold. I've ordered a Dehumidifier that I'll start running. Before I build the system I intend on cleaning the mold with bleach, patch and seal walls to hopefully kill the Mold issue.

My biggest concern is going to be keeping the tent in the Optimal Temp range and Humidity Management due to my Climate. I will not be starting with a chiller or AC due to the current winter months, but will be adding onto the system at a later date. I will start out running a Dehumidifier, even this time of year we still deal with 60-80% Humidity.

With all the above in mind and looking at the drawing what would you suggest for lighting in a 8'4'x8' tent with a 6 Bucket Under Current System. I looked at the local store today and 2-3 600w CMH or 2 1000w CMH Growers Choice came recommended by the owner. They seemed like a well made fixture with some added safety features and dimmers. I've also looked at a few vented light fixtures online that seem like a better option for my situation. I'm pretty sure COB is out of the equation cause I've got quite a few projects going on at home already and dont have time to build a light. All the pre build fixtures online get pretty expensive for that coverage area. I'm open to suggestion on type or wattage of light as I'm not used to growing in these elements.

Any tips on the plumbing, pumps, fans etc?

Thanks in advance to those who take the time to read and respond.

I'm not super super experienced but I've looked at a lot of systems and seen peoples failures and tried a bunch of different stuff myself. While you seem to be on a great track so far and have a pretty good idea of what you're doing, I do have a few suggestions based on personal experience.

Totally agree on cleaning that mold and your space first. I cleaned all the walls and scrubbed the floor with bleach and even painted it all too.

Your main res is 5× what you need, itll be at the same water level as everything else, use a smaller tote. I have a 12 site that's around 90 gallons total and my outside res has maybe 10. If you're going to use a top off tank, I wouldn't use a res much more than twice the size of your sites.

Also. I'd ditch the air pump and stones and go with waterfalls. I switched from airstones. Pretty much keep it how you have it but turn that return line into a feed line along the top. Just run a 1" line down the middle and branch off to 1/2 or so into the sites.

You range of pump is good imo. If you go with the 5 gals I'd go on the lower end of your range. I use around 800gph per 45 gallons of water in 6 sites.
I'd go slightly larger on the fan personally. That one should control smell ol, but if you go bigger you can adjust it to help control inside environment.

Look around the hydro/dwc section and read through some of the threads. Check out my stuff and @Airwalker16 for some ideas.

Here's how I'd do it, pretty sure one of airwalkers setups is similar.

I like 600 watt lights myself. I have 1000 watters on the shelf. They make too much heat for my taste.

https://www.rollitup.org/t/i-gotta-lose-the-air-pumps-how-plus-my-awesome-mini-dwc.960807/page-3#post-14262160


Much more in that thread too.

Word of advice, invest in a chiller... 1/2 HP for an 8X8.

You can find used ones on eBay fairly commonly for quite cheap.

Airwalker16 said:

Word of advice, invest in a chiller... 1/2 HP for an 8X8.

You can find used ones on eBay fairly commonly for quite cheap.

Click to expand...

thats way overkill. I use a 1/4 HP for whats nearly 3x the volume of what his would be if he uses the 7 gal buckets and it does a great job.

fragileassassin said:

thats way overkill. I use a 1/4 HP for whats nearly 3x the volume of what his would be if he uses the 7 gal buckets and it does a great job.

Click to expand...

Oh I thought he was using totes. Still. 1/2 HP would work well.

Airwalker16 said:

Oh I thought he was using totes. Still. 1/2 HP would work well.

Click to expand...

He said 5 or 7 gallon bucket somewhere, I think it was labeled in the picture.
Itll work great yeah lol. But a 1/4 is around $350 and a 1/2 are $8-900.
It was keeping mine at 66F for a while.
I've slowly gone up over the grow and I'm comfortable in the 68-70 range.

fragileassassin said:

He said 5 or 7 gallon bucket somewhere, I think it was labeled in the picture.
Itll work great yeah lol. But a 1/4 is around $350 and a 1/2 are $8-900.
It was keeping mine at 66F for a while.
I've slowly gone up over the grow and I'm comfortable in the 68-70 range.

Click to expand...

I've found several used 1/2HP on eBay for 2-400

fragileassassin said:

I'm not super super experienced but I've looked at a lot of systems and seen peoples failures and tried a bunch of different stuff myself. While you seem to be on a great track so far and have a pretty good idea of what you're doing, I do have a few suggestions based on personal experience.

Totally agree on cleaning that mold and your space first. I cleaned all the walls and scrubbed the floor with bleach and even painted it all too.

Your main res is 5× what you need, itll be at the same water level as everything else, use a smaller tote. I have a 12 site that's around 90 gallons total and my outside res has maybe 10. If you're going to use a top off tank, I wouldn't use a res much more than twice the size of your sites.

Also. I'd ditch the air pump and stones and go with waterfalls. I switched from airstones. Pretty much keep it how you have it but turn that return line into a feed line along the top. Just run a 1" line down the middle and branch off to 1/2 or so into the sites.

You range of pump is good imo. If you go with the 5 gals I'd go on the lower end of your range. I use around 800gph per 45 gallons of water in 6 sites.
I'd go slightly larger on the fan personally. That one should control smell ol, but if you go bigger you can adjust it to help control inside environment.

Look around the hydro/dwc section and read through some of the threads. Check out my stuff and @Airwalker16 for some ideas.

Here's how I'd do it, pretty sure one of airwalkers setups is similar.

Click to expand...

Thanks for the input.
I'll go with your idea and change to the waterfall design. Not having to listen to that air pump will be nice. Have you had any issues with your system? I'll be running 6 sites, Reservoir and Top Off tank, will a 800GPM be enough or should I go with a larger pump with a ball valve to control overflow?

I know the reservoir's seems alot bigger than needed but I've read a few builds where guys claim it helps extend the life of Reservoir for water change outs (Not sure if this is true). I understand this will cost me more money for Nutes though. This will also give me the option to add onto the system at a later date without to much modification. I work away from home so I'm gone for 5 days at a time, while I'm away my wife will be helping to run the system. With the above in mind, I was hoping the larger Reservoir might make it easier for her? Not sure if my logic is right there....lol..

Also taking your advice on going with a larger fan, when I first started drawing this up I had intended on using LED type lighting. With the CMH or HPS I'll definitely need more air movement to hopefully regulate the heat. I'm thinking 8" or 10".

I really appreciate the tips. I'll probably make some changes to the drawing and post again, it always helps to have another set of eyes with more experience to check for design flaws.

70's natureboy said:

I like 600 watt lights myself. I have 1000 watters on the shelf. They make too much heat for my taste.

Click to expand...

Thanks What brand/type of lighting are you running? I'm already worried about the heat so I figured the 2 1000w would be difficult for heat Management.

I thought about just running the 1000w dimmed to 600 for Veg and turning them up some for Flower. I've heard this is not the best thing though since your not using the bulb as intended?

Airwalker16 said:

Word of advice, invest in a chiller... 1/2 HP for an 8X8.

You can find used ones on eBay fairly commonly for quite cheap.

Click to expand...

I know I'll be needing a chiller but was hoping to get by in the colder months without one. I'll start pricing them out since I know this will make my life much easier. Think I'm going the route of the 8x4x8 instead of the 8x8. Total gallons will be somewhere around 60-80gallons depending on the Rez size I choose. I'm sure a 1/2hp one might be more efficient since it wont run as hard in the hotter monthes but will have to see about my budget. Do you recommend any trusted brands?

Thanks

i would think about a 630w de cmh per 4x4.

I've got a stack of digital ballasts that failed after a year or two. I went back to the reliable magnetic ballasts. I didn't like the RF interference anyway.

Quantum boards are the way I would go. Spend the money now so you don’t buy more than you need later.

If you like the experience of building your own equipment I would either go with cob fixtures, samsung f564b fixtures or quantum boards. I love my samsung lights!

shawnery said:

If you like the experience of building your own equipment I would either go with cob fixtures, samsung f564b fixtures or quantum boards. I love my samsung lights!

Click to expand...

Timbergrowlights.com offers both DIY and pre built. They also have a coupon code: RIU for $25 off your order.

I’m not paid by them but I’m a super satisfied customer. Dan even helped me out with finding exactly which light I wanted.

I'm not sure why you expect your water volume to be nearly the same as mine with a system 1/3 the size. My system is 90 gallons of water total with it an inch below my pots. I have 12 17 gallon sites and a 55 gallon HDX box control res.

And dont go any bigger than 800gph with 6 sites, even with that you may have issues with a chiller keeping up with your volume.

I touch my system 1 time a week and left it go for 3 months with just top off this grow. Youre just over complicating things imo. If youre going to use a top off res, you dont need much of a control res at all like my veg setup.

E.Texan said:

I thought about just running the 1000w dimmed to 600 for Veg and turning them up some for Flower.

Click to expand...

Get a 600w mh bulb for when you want to veg, and a 1k hps to bloom on the same setup.

shawnery said:

If you like the experience of building your own equipment I would either go with cob fixtures, samsung f564b fixtures or quantum boards. I love my samsung lights!

Click to expand...

Would like to build them, but time is very limited right now. I'm currently renovating two rooms in my house also. I'll start checking out some You tube videos. Still leaning toward the CMH though.