Tray never fully drains

So, I am doing flood and drain, and my tray never fully drains itself of water. There is always about a quart of water floating around in puddles near the drain and on the sides of the tray. This water just sits there for hours under my light, is this going to cause algae? Also, my pump is so strong that it fills the tray within a couple minutes, so the rest of the 15 minute pump time, my water pump is just pumping air. How long before my water pump burns itself out? Thanks guys.

Did you put a little slope to the tray? It should slope 1/4 inch for ever 12 inches of run. So if the tray is 4 foot wide, it should be 1 inche lower on the drain side. As for the pump, I would get a digital timer that you can set from 1 minute to 24 hours, or just get a smaller pump. But i would get a digital timer. Time how long it takes to fill the tray and that is how long you set the timer to run the pump.

Yeah the tray is sloped, it's about 1.5 inches higher at the non-draining end. My tray is the one that has all those channels in it for "water-flow", but all those do it seems is prevent water-flow.

I will try to find a digital timer for the pumps, but in the meantime, are my pumps gonna blow up fairly quick or will it take a while?

Also, another side question: When I do my first res change, I was thinking of getting a very long hose and running it from my res to my bathtub to drain the water, instead of taking an hour bailing out 2 quarts and running back and forth. Do you think that when I turn on the pump (633 GPH), the hose will go wild and spray water everywhere before I have time to run into the bathroom? (about 15 seconds)

633gph is a pretty good sized pump. go to the hydro store, or the hardware store and by a Ball Valve that will fit in the hose you want to run to the bathroom. This is exactly how I drained my hydro system when i was running hydro. Close the valve, turn on the pump, walk the hose and valve to the bathroom and turn it on. When it starts blowing air, turn the valve back off. Walk back to the hydro room. and reconnect your system the way it was.

Can you show some pics of your set up ?

As far as your hose situation goes - you could
1 run an extension cord from pump to bathroom
2 place something heavy enough to hold down the hose
3 ask someone to help

As for draining - you have it backwards. The pump side should be lower. The pump will back flow when it is not pumping, draining that last little bit of water. I use only a screening cap on the pump side and extensions to equal the height of the water I want in the tray when full, on the overflow.

As for your pump filling the tray to fast, A smaller pump would be the ticket. I use a 396 for each 4x8 tray with a 3/4" feed and 3/4" drain. This size seems to balance the flow. Hope this helps

genisis, if my tray was sloped the wrong way, I would have 23 gallons constantly sitting in the tray, and I think I would realize my mistake pretty quickly without having to go online .

Anyway thanks guys for the responses. I still don't know why my tray won't drain though, but it appears to be a design flaw in the tray, with all those stupid channels and ditches that do the opposite of what they're supposed to: http://www.atwaterhydro.net/product_p/hyft44.htm

I'm just very worried about algae, because I won't be able to cover my tray for another week. Will I encounter algae soon with these little puddles sitting there?

Where did you put the drain hole? Pics would help....that link didn't show much, but it did say it had multiple drain levels...

The guy at the hydro store drilled the holes, they are at the very end in the center. The other end is on an elevated side table. The pump end is resting on the reservoir. Sorry I'm unable to post pics at the moment. It's a very simple, basic flood/drain set-up though.

I'd like to see the drain nipple....does it stick above the surface of the tray bottom?

The reservoir needs to be below the flood table/tray. When the pump shuts off, the water should drain back through the pump. There will be a small amount of water left in the table/tub/tray since the flood and drain fittings are slightly elevated from the bottom....don't worry about this.

Beagle I think that answers my question, there is a little water near the fittings and a little in the channels, probably because the fittings are on a washer, so that 1/8 inch thick or whatever makes the difference. It's good to know I don't have to worry about algae because of that.

Also, in the third picture is just so you can see the plants, I'm wondering if I should start lowering my light yet? (1000W HPS) The clones were rooted when I bought them and they've only been in the setup for 4 days. The light is currently 4 feet above, and the one in the middle back looks like it might be stretching up towards the light. Should I lower it a bit?

If your worried about algae, you can cover your flood table. Even a short layer of hydroton would do.

Yeah I'm going to cover the tray, but can't yet for another week or so because I'll be putting half of the plants in the other tray. I put a bunch of hydroton in it at first but it floated around and settled under the pots, big pain in the ass, so I took it all out. Was thinking of getting a coco mat but they're kinda expensive.

if you want to fill with grorocks, you gota fill to above the flood level, else the rocks on top will be flooded and algae will grow on them. the tray will always stay wet much like a tub after a shower. algae will grow. cover the table with a lid. i always have a hole on the side which circulates water back to my res so i flood my table in few minutes the rest of the time is recirculating nutes. however my control res is bigger than my tray so the water level never goes below my pump. you should never let the pump working in air, it will burn real soon

Algae will not hurt your plants. All it will do is maybe eat a little nutrients. You can take Panda Film and stretch across the tray with holes for where the plants would be. OR, you casn just live with it. When i ran Hydro, I used to keep a nice clean sponge there. that I could get lightly damp and then wipe down the Algae in the tray every once in a while.

Ok, so I'll be buying a digital timer for the pump in the next day, so I can set it to be on for only 2 minutes (that's how quickly it fills up). Is it bad to only have the plants drinking for 2 minutes before it drains?

Also, could somebody please tell me if I should be lowering my light yet? It's a 1000W HPS, 4 feet above the canopy. These are 5 day old clones but they were already rooted when I bought them. Is it time to start lowering?

Your reservoir is too small if you pump it dry when watering.
You should have twice what it takes to fill your table in your reservoir.

angelsbandit said:

Your reservoir is too small if you pump it dry when watering.
You should have twice what it takes to fill your table in your reservoir.

Click to expand...

WOW!!!! About time someone caught that. hahaha. Even i never said anything. DOH!!! Sometimes the simplest things are missed.

Yeah you're right... I thought a 27 gallon reservoir would be big enough... Al b. fuct uses 4x4 trays like me and uses a 33 gallon res, so I guess I should'nt have under-shot it. It's too late now so I'm gonna have to get those digital timers. Is 5 minutes of drinking time not enough though?