Backyard Aquaponics
A place to discuss aquaponics

Ah cool, I kind of skipped over the spreadsheet instead of squinting at the teeny text. I had a blackbird snaffle several of my best-looking strawberries just as I was thinking they were about ready to pick; the ones I got to first tasted so good I resented every one he took! Netting is definitely the way to go.

And thanks! Stoopid arthritis is interfering with closing up my hoop house right now, every time I have an opportunity to work on it the weather changes and that kicks my joints into complaining again. Still a heck of a lot easier than dirt gardening, though!

Not sure what is happening with my water chemistry. PH is dropping rapidly which is a worry. I understood that this happens once the full nitrification process is happening with fish but I don't have fish yet.



25/7/17
pH 6.80 Ammonia 0.25 Nitrites 0.50 Nitrates 80.00 - 2 days after adding a desert spoon of Urea. Also added 300 litres of rain water to top up sump tank 2 days ago prior to testing


27/4/17
pH 6.40 Ammonia 0.25 Nitrites 0.25 Nitrates 40.00 - did a sprinkle of blood and bone (50gr per growbed and watered in lightly)


28/4/17
pH 6.00 Ammonia 1.00 Nitrites 0.50 Nitrates 160.00

The pH seems to be dropping fairly rapidly, but I am now seeing the urea converted to ammonia as expected. Nitrates are way up again tonight but there does not seem to any take up by plants. Plant growth has basically stalled for about 2 weeks and this is why I added Blood and Bone for any missing trace elements to try and stimulate some growth. I have been adding about a capful of regular seasol (not Powerfeed) per day to the ST.

Still no fishies yet as I don't think it is fully cycled yet.

any ideas why the pH is dropping so quickly??

I saw very rapid pH decrease in my first system before I added fish- it just means that the bacteria are really getting stuck in! You still have nitrites, so are not yet fully cycled, so you still need to wait before adding any fish.
Add some K2CO3, Ca(OH)2, CaCO3 (doesn't have much of an effect) or KOH. I'm currently adding 100g of KOH per day to keep the pH in the low to mid 6 range in my large system.

Gordon where do you get your potassium hydroxide KOH from?

A local chemical supply company, I've just ordered another 25kg this week. It should be pretty easy for you to find locally, any cleaning chemical supply company should have it.
I was hoping to get K2CO3, but they have not been able to get any in a small quantity, and I don't want a ton of it

I have used these guys before: http://stores.ebay.com.au/Rungood-Labs

They were quick and easy to deal with and seem to be reasonably priced.

My Nitrites reached zero - yippee. Nitrates still at 80-160ppm





Plants are alive but not progressing that well after a month. Hardly any growth. Not sure what is happening there. Added some Blood and Bone three days ago but no pick up yet.
I added some more Urea to check the ammonia levels and Nitrites and see if the levels drop in 24hrs. PH is still low at 6.0. Tried adding some pulverized egg shells after boiling and baking, but has made no difference and from what I can see none has dissolved.

I will get some hydrated lime tomorrow and see how that goes. Anyone know how much I should add. I calculate the total system water volume at about 2000 litres give or take.

Keep in mind that urea has to break down into ammonia before the bacteria can get to work on it, and that could take a few days.

Shell grit has minimal effect in my experience, I've put kilograms of it in my systems with negligible change in pH. because it dissolves so slowly.

Dissolve say 20g of Ca(OH)2 in a couple of litres or more of water and spread it around in your system, it isn't very soluble in water, so needs to be mixed with a lot of water so that you dont get too much settling on the bottom of the FT.
Avoid getting any in your eyes, and also on your skin, where it wont have much effect until it gets wet, but then you need to remove it ASAP! Measure the pH a few hours later to see what change there has been, and again the next day before you add any more.

Bit of an update.

I have had some water chemistry and plant dramas - see here viewtopic.php?f=3&t=28558&p=553419#p553419.

While I was getting this sorted out I got on with building. I got hold of some polystyrene foam 50mm sheet cut to size and insulated the fish tank. I hot glued the corners to form a rigid box around the IBC and then lined the outside with silver builder's foil and tucked it over the top.



I then made up some timber panels and lined 3 sides the same as my grow beds. I ran out of the brush box flooring for the fourth side so I will have to do that side in plywood in a frame. Not a big worry as it faces the bush and the plumbing all comes out that side as well as the IBC drain tap so holesaws will be easier through ply than panelling anyway. All good.


I got another piece of foam for the top but haven't yet figured out how I am going to do that. I will probably make up an outer frame and line it with ply and then cut an inner hatch in the centre to access the Fishies. Any ideas appreciated.

While all this building work was going on on my system was slowly sorting it self out and today I had zero ammonia and zero Nitrites. Nitrates were also down too. pH was sorted as well and steady at 7.4.

Yay - cycled.

So off to see Steve for some trout. Big shout out to Rendang for answering a lot of my questions and showing me his system and his fishies and veggies. Just proves its all not a myth as I was starting to have my doubts.

Because I am a bit of a worrier, I decided to start small and then build up slowly so I am only getting 10 trout to start. Once I am confident they are surviving OK with no dramas, then I will get some more.
Steve said he had some fingerlings but I wasn't expecting the size of them. Some would be close to 180mm

Soooo - after a nervous drive home for an hour I am now the proud owner of 10 trout who have now settled in nicely after an hour of acclimatizing and are now happily swimming around in my murky water and having a quick feed. Hopefully that will clear up soon.
they are now all tucked up in bed

You may need to up the water movement or aeration for the trout, the tank water looks awfully still but take my comment with a grain of salt since I'm not certain of exactly how you're system setup operates or if you shut the pump down to photo the fish.

Scotty have a look here and let me know thoughts about the aeration.
https://youtu.be/BvMRFlP3flM. This is my normal pump operating with a small spray bar. I think my return line from the sump may be undersized at 20mm. I am thinking to up size it to 25mm or 32mm the same as the pump outlet size.
I have a 35 litre per minute air pump and 10cm airstone on the way just in case.

Happy to hear your advice

Well the 10 fishies survived over night. So far so good.

Ammonia still zero, Nitrites are up slightly to 0.25 and Nitrates steady 40-80ppm. To take precautions I salted tonight to 2ppt (4kg in 2000 litres) and added to the fish tank. I left it half an hour and then stuck my action camera in and had a peek. They all seemed to be swimming around happily and all active. its all a bit hard to see because it is murky brown down to the bottom.

I gave them a small amount of food last night to settle them and they ate and another small amount this morning. NO MORE til the nitrites drop.

PH has swung back up to 8.0. I think I have a problem with brown algae and this must be causing the pH swings.

Anyone know how to get rid of it??


Here's another shot in daylight.




On another note i harvested my first fruits tonight. I know, I know don't get all excited, its not much to write home about, but hey its first fruits and I am excited.

Not a huge thing, salting was a good idea for the fish but 1ppt would have been sufficient and it may have been better to withhold feed instead because of the fairly low nitrite levels and because strawberries are very sensitive to salt concentrations - tough call though (Even 1 ppt might have been too much). The effect on strawberries is usually pretty slow decline.

The brown algae could just be the normal biofilm that forms on the sides of the tank but blocking more of the light would help if it's algae. This includes blocking the light through the sides by either painting them or covering them with something. Keep in mind that if this is brown algae it will be using oxygen at night and it's also probably using some of the ammonia. Dead algae breakdown will also consume oxygen. It didn't look really bad yet but sometimes a gradual die off is what you want so the filter can process it well and the oxygen levels don't go down.

Algae can cause big pH swings .

It's pretty tough to tell on the aeration - you probably already know this but I'll mention first that warmer water holds less oxygen than cold water so it's more important to aerate when it's warm. Looking at the aeration of your tank it's probably fine for the 10 you currently have but I'd increase it if you add more fish or get near the trouts upper temperature threshold. If you see the fish near the surface gulping air or they look really sluggish I'd up the aeration for that as well. I'm not currently growing trout (I have catfish and bluegill) and others may have a better idea on this than I do since they are currently growing trout. You may want to look at other IBC systems as well. Other than in the forum, there may be something in the IBC of Aquaponics since this shows a lot of IBC systems - http://ibcofaquaponics.com/ and just looking at the aeration on some IBC systems on youtube might help.

Thanks Scotty. I have my back up aeration system running off battery and being charged as well to give extra aeration until my air pump and stone arrive. Yeah I realised about the strawberries, but at this point the fish take precedence.

I certainly didn't want a HSM moment. I have the fish tank and sump tank fully covered. The only thing that could be letting in light now is the EFF. It's white so I will cover that with some shade cloth shortly. I can see down in the water about 400mm so it's not too bad at moment.

Hopefully it will die off slowly over the next few days. I will stick a tape measure in and see what I can read each day.

For future reference you should consider using Calcium Chloride (CaCl2) instead of Sodium Chloride (NaCl) to treat for nitrite poisoning. Both the sodium and chloride components cause problems with strawberries. The Chloride is what helps with nitrite problems so switching to the calcium salt might be better overall. To counteract the chloride up the nitrates and to counteract the effects of sodium up the potassium. This explains in additional detail - http://www.haifa-group.com/knowledge_center/crop_guides/strawberry/special_sensitivities_of_strawberries/