Backyard Aquaponics
A place to discuss aquaponics

Hi all,

I'm in the process of building a my first system. 30 gallon aquarium and a tank full of hydroton. I have a solid submersible pump and everything configured. However, my issue is this: I have an old mechanical timer that I want to use for the pump. Ideally, it'd run 15 minutes to fill the media bed and then be off for 45 minutes of draining. Unfortunately, the timer is old and has "slowed down" so that the timer's original 15 minute increments are instead 30 minutes.

Is it going to harm my system to flood for 30 minutes and then drain for 90 minutes, instead of the recommended 15/45?

Thanks!

Probably OK... but would likely depend on how hot it gets... ie. How fast the surface layer dries..
Lie.. deep rooted plants would be OK... just planted ones with minimal root structure may logically suffer..

But.... really... if the timer has failed, is it not obvious that it will get worse, unless you can fix it..
What would a new timer cost .... 5 to 20 bucks.. or check out the oval Op-Shop for used ones..
..
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Thanks for the reply!

I'm not too worried about the temperature since it'll be inside a climate controlled house. Eventually, I'm definitely going to pick up a nice digital timer that I know will never degrade, but I just wanted to make sure I could get started with what I have without dropping the $$.

For now, I'll just pay extra close attention to any seedlings or newly added plants to make sure they stay damp.

The timer electronics may last a reasonably long time, but it's the relays that fail. I've had 2 fail due to sticky relays within 12 months.

Hi Truavatar,

is it seriously worth worrying about playing around with an old timer for a 30 gallon system that is probably running a fairly low wattage pump anyway? eg. the BYAP systems only supply a basic household Arlec brand pin based timer for everything up to their 3000 series pump systems.

Surely at hourly rates of fiddling with something to be replaced anyway, spending $10-$20 (probably even less if you want it to) makes a lot more sense.

Maybe it would be different if we are talking about a major pump system where power draw and load was more significant.

with many systems I suspect that there always a bit too much over thinking and not enough on KIS and uncomplicated.

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As a useful suggestion - I learnt my lesson with digital timers that can be affected by power flickers and drops. I use a pin style timer so that keeping the time is no longer an issue. It simply comes on for period and then off, even after a power interuption and though it may be 2 hours out the cycle simply repeats as long as power is running.

Im running a miniature indoor system using crayfish and a drum.
I don't have my flood and drain system on all the time, I started by just flooding and allowing it to drain once every 3 hours. Should I keep my pump on and my grow bed flooded constantly? I am using a river stone substrate with a bit of perlite. It's quite a small system so the planter placed above the tank drain directly back within a matter of 5 min.

This is what I am attempting to use for a timer.

http://www.ebay.com/itm/Repeat-Cycle-Timer-40min-Hydroponic-Aeroponic-EZcloner-/291253214262?pt=US_Hydroponics&hash=item43d00b5c36

It has 40 on/off switches over a 40 minute cycle.

I am currently using a pin with half hour increments with my aquariums. I have ran it in several combination. The longest off time was 3 hours. I havent noticed any adverse effects with the extended off time. Currently I am running half hour on/ half hour off with both my indoor and outdoor systems.


I am ordering one or more of those pin timer that you posted a link for, Pondsucker... It is just what the doctor ordered.

As for extending your dry time, there is nothing wrong with that. If you look into old school hydrophonics they will suggest far less flood and drain cycles per day. AP in most cases forces many flood and drain cycles to turn over the system volume and to maintain constant water flow to the fish.

I'm a complete newb though and I don't even have fish yet... so before you take my word do some more homework, but I'm pretty sure the above is accurate.

Check out this build, Pond Sucker.

I just completed one of this mods, and it was super easy. Total cost $7.00 for timer and rubber washer. The segments are 50 seconds long. It takes 2 segments to fill my grow bed, and it is off for 4 segments. I am real happy with the results. This will allow me to flood and drain my system around 8 times an hour versus the once an hour with the unmodified timer.

Pretty cool, sounds like it could be a side business considering the cost of the one I purchased which does about the same as yours. Now lets find a way to make that timer open and close a valve on an AP system. Its been done but just saying... that would be the next step on my list.

Ok.. I was off in my calculations. With the cycle above, 2 segs on / 4 off, I could get 32 flood and drains per hour. I wound it back to 18 per hour.

Thanks for the OP, truavatar. With out it, I wouldnt have accidentally ran across the videos.