New kit, CHOP Constant Height One Pump

[Hamish]

Hi Murray - do you have concrete blocks stacked inside the sumps to support the grow beds?

[DaveOponic]

Water flows from the fish tank by gravity to the grow beds, the grow beds fill, the auto siphon delivers the water to the sump below where the small pump delivers it back to the fish tank.

Murray, from your description it sounds like you are using only one pump. If the water flows by gravity to grow beds then how is the fish waste pumped out of the tank? i.e. is there a pump in the fish tank? With your setup it looks like you would need two pumps.

In both my AP systems, the water flows by gravity back into the fish tank. So it looks like your pump is in the sump (excuse unintentional rhyme)

The other thing I don't get is why your grow beds are so low?

My grow beds are a full metre in height. One of the big advantages of not growing in soil is not having to bend down on your knees to do the gardening. So, what advantages are there in this setup. It seems like you'd need a pump in each sump.

[Murray]

Hi DaveO,
Top of the Grow beds are 700mm from the ground. Nice working height.
The Fish tank is taller than the grow beds so the water flows by gravity from the fish tank to the grow beds.The water in the fish tank comes up from the bottom of the fish tank via an internal up stand.
The up stand is able to be removed for cleaning etc
In this current model each sump has it's own small pump sending the water up to the fish tank.
I have spent some time trying to do a drawing to illustrate, but all have been a bit messy.

Hi Hamish
Yes the concrete blocks that support the grow beds are standing inside the sump

[Dufflight]

Thats a strong sump.:D

[DaveOponic]

Yes, now I look at the photo again I can see that they are higher off the ground than I thought.

Is it better to use gravity and a central stand pipe/drain hole to suck the waste off the bottom of the tank? Is that the reason you have the fish tank higher than the growbeds?

I have been puzzling over this. Since I put fish in my 1000 litre plastic tank I find I need to vacuum fishy poo off the floor of the tank two or three times a week as it builds up. My pump is in one corner of tank. I tried a stronger pump
but won't suck the fish poo away. I put in a second pump to create currents but still accumulates in another place.

Hadn't thought of gravity drain as I was reluctant to drill holes into my $ 250 plastic tank. (When I want to sell it on leaving this country better to have no holes in it)
Dave

[DaveOponic]

I have bought about 4 Chinese made submersible pumps in the last 12 months. Two died after about 2 months - broken impellers - no replacements available.
The other two both leaked and gave me a solid buzz in the water.... i have now learned to switch off the power before sticking my fingers in the pond!!!

I also refuse to buy any more pumps made in China.

I now pay more and buy EHEIM German made, 3 years warranty and a full range of parts available. I have had one past the warranty period in continuous operation for over three years now and only had to replace an impeller.

Not a lot of choice though here. But if I do have a choice I won't buy a Chinese made product. The one pictured on this forum is available here at about half the price quoted on the web page.

[Murray]

DaveO,
Pumps are the curse of Aquaponics. If only we could find a way to move water without the need for pumps ...:rolleyes:
I have had good quality Italian made pumps fail and low cost Chinese pumps as well.
We did have a source for German made pumps but that importer went out of business.
Fish poo on the bottom....It is not such a problem with Silver and Jade Perch. Their solids are dissipated well in the water anyway. I have a long handled stiff broom that I use to scrub the bottom and sides of the tank once every week or two.
Even the Murray Cod tank cleans ok this way. The Murray Cod are great pooers. They deliver large volumes of solid material compared to the Perch.
It is a bit more difficult to get rid of in the tanks of the CHAP systems as the pumping action is much more passive than in the Murray Cod 2300 ltr system that has a 7800 ltr ph pump sitting on the bottom of the tank.

[wild]

Hi Murray,

Love the concept of CHOP. How well would CHOP work using larger tanks/beds? For example, using one of your 2300 ltr parabolic tanks and 4 500 ltr growbeds? I would assume that CHOP would work as long as you have the height of the growbeds correct (regardless of the size of the system). However, are there any disadvantages in this type of a system??? On a side point, the dimensions of the 2300 ltr parabolic don't appear on its product detail page.

Cheers, Andrew.

[nick]

i have changed from a gravity return to th big tank to a CHOP system and my water is only clearing to a certain point. i can see through it but not anything compared to how clear my old system could be. it just seems to have a very large amount of suspended solids.

I think maybe running it a bit longer might solve the problem and will give that a go in a little while. also to get the fish out of the tank is going to be a bit more difficult than before.

Nick

[fishfood]

A friend uses it with 2 3000 litre fish tanks 6 ft high 1 is running 4 bath tubs and some recycle tubs the other is running 12 bath tubs so yes it works and very successfull

[Murray]

Hi Wild,
Yes it will run with the bigger systems. We did an install last Friday using the Parabolic tank + 4 x 585 ltr grow beds and 6 x 250 ltr grow beds.
Needs bigger pump though for that system. The Para fish tank is located in a shed about 10 mtrs away from the greenhouse and the greenhouse is 11 mtrs li\ong, so the water had a long way to run by gravity.
We used 90mm pipe for that part of the system stepping down to 40mm at the grow beds.
The return line from the sumps is 25mm pvc , but we have found that we need to step the size of the pump up to get the water back to the fish tank in sufficient volume.
One disadvantage is the fish tank is always full, so it makes it a bit harder to see the fish if the water is not really clear. But that is also one of the big advantages I reckon....If the pump has a bad turn the fish tank will always be full of water.....more safety for the fish.

.

[Jimbo]

OK Murray
you have me intrigued with the CHOP system.
As I am unable to find another DR1 timer and as it seemed to me to be the best thing since sliced bread re growbed flooding- much better than using float switches- I will have to find a better way.
I am on solar power so low pump running load is crucial for me.
The only part of your neat animated demo I can't quite work out is the auto syphons. Is it a bell syphon type or the old looped poly tubing?
Do you have a diagram of same?
Jim

[Jimbo]

Hi Murray,
ignore previous post - I have found the diagrams elsewhere on this site and will work out how to build a version to experiment with
Cheers
Jim