Backyard Aquaponics
A place to discuss aquaponics

Water tests today
ammonia 0.25-0.5
nitrite trace
nitrate 10 - 20
ph - 7.4
temp - 12C
the fish seem a lot happier. They didn't feed at all yesterday. I offered them a couple of tablespoons today and they fed well. Hopefully they are going to be okay. My plants look like they are starting to suffer from some nutrient deficiencies... yellow leaves with black spots. My chinese cabbage leaves are very pale and there looks like their is scale (little raised pimples) on my brocolli leaves. I have pulled out the weak plants, taken off the yellow leaves and planted some more seeds. Hopefully the seasol will start to make a difference soon.

When fish die to they usually sink or float? The dead fish didn't smell so I am assuming that it was recently dead. I wonder if that is what changed my ph so quickly. It is good that it has dropped a bit. I think the lower ph will give the plants a fighting chance to take up some more nutirents.

Some sink, some float. Typically they float more as they decay and gasses build up.

Glad the fish seem happier!

I'd be happy to feed quite a bit more with those readings.

How much seasol are you adding?

I used the seasol as a folier spray. I mixed it according to the directions on the pack and sprayed about 4 litres onto the three grow beds.
I am a bit confused about the feed levels. I weighed five fish today and the average weight was 87 grams. I worked out that with 74 fish I should be feeding around 56 grams a day. I have been feeding them around one cup a day... approximately120grams. Should I be cutting back on the feed rate? They seem to be eating it all. I am feeding them a lot slower so they have more time to pick up each pellet before I add more.

With fish that size, you can probably feed at 1.5% without trouble. It's only once they get older that fat becomes an issue.

I tend to feed them as much as they can take while young, then back the feed off once they get to a good size.

Your filtration seems to be handling the feed rate... just back the feed off if you get a spike..

Thanks for all your advice. I haven't lost any more fish. The one that died must have been damaged by something. I will continue to feed at the current rate and see what happens. How often should I be adding seasol to the system? Do people normally add the seasol to the water or as a foliar spray?

About once a month... either as a foliar spray, or direct to the tank..

I recently did the same thing to my tank. Added chelated iron and seasol together. The next day the tank water was yellowish and cloudy. It lasted for a few days. Funny thing was when I pulled up the PVC pipe I had in there, it had some uneaten food inside. I had goldfishes in the tank at that time. Maybe the combination of chelated iron and seasol affected their feeding pattern, not sure.

Anyway, I put in trout shortly after, and after a day the water became almost crystal clear.

Not sure about you, but I will be thinking twice of putting that chelated iron shit again. At least possibly less scoops next time, but probably not. My tank is still coated with some yellowish brown stains. But on another thread, some members are talking about using rock dust, might be worth considering after your system is more stable. Not sure about the effects so you might want to find out more first.

One scoop is sufficient... in about a 1000L.... it's a micro trace element..

One scoop of Chelated iron or Rock dust?

Use the small scoop that comes with the Chelated Iron... and sprinkle a handful of rock dust over each growbed...

I like to add the Maxicrop and the chleated iron to the grow beds right where the water enters them, that way it can mix in the bed and only what gets suspended in the water will make it back to the fish tank. The Water still turns to quite a tea color (dark brown from the Maxicrop and kinda an Orange from the Iron) for a few days but never goes cloudy from it.
I've been using a heaping tablespoon of the Iron for each of my 8 foot by 3 foot grow beds (about a cup in total across all my outdoor grow beds) and about a quart of Maxicrop spread around all my outdoor grow beds. I think I could be doing the dosing about once a week but I usually only do it about every three-four weeks. Foliar spraying is probably the most effective way to help the plants so long as the weather is not too hot (burning plants with sprays is common in hot weather) but many of us are too lazy to bother spraying and just dump it in instead.

If in doubt about dosage rates, go kinda light, you can always add more later if the plants are still showing signs of deficiency.

If in doubt about the dosage rates... read the label... lol

If it sounds like too much when you extrapolate... halve it..

I think I will add two spoons of the iron next time. My plants definitely look like they need something. It is interesting that ivansng had a problem with his fish being affected by the addition of seasol and iron. I think next time I won't add them both at the same time...maybe a week apart.

What is rock dust and were would you purchase it from?

The fish are feeding well and seem back on track