Backyard Aquaponics
A place to discuss aquaponics

Everything seemed to have settled back down a few days ago, however over the past couple of days a number of the silver perch have been vigorously “flashing’ and rubbing themselves on the floor and sides of the tank (they seem to be rubbing their head region) or sides. They are feeding well but getting territorial again (a few days ago, they had started to shoal). Also, one of the larger perch has settled on a ridge on the side of the tank and doesn’t look too good.

The goldfish seem fine, and I can’t see any obvious sign of white spot. I am still to buy a nitrate test kit, but Ammonia is reading 0 (personally I would have expected a small reading). Water is crystal clear.

Other than test for nitrates, does any one have any thoughts of what the issue could be / corrective measures I should be taking (thanks).

I think from memory that is ich. VB had the same problem with his silvers I think. Wait for one of the tech heads, but I think your best best it to dose them with salt.

Thanks Monya, just need the tech heads to advise on salt dose. I have a 1360L tank....... (BTW assume the plants will be OK)

http://backyardaquaponics.com/forum/viewtopic.php?t=309

this may help

Sounds like Ich to me. Also could be worth testing for Nitrite as high levels can also stress the fish. Perhaps change 50% of your tank water or buy yourself a test kit.

OK so 1 teaspoon of salt per 1 gallon (4 litres) seems the way to go, so by a quick back of the envelope calculation, I assume 1 tsp = 5g x (1360L/4) = 1.7kg

Some literature suggests this dosage each 12 hours x 3.

You could just give them a salt bath (in a smaller container) for a few minutes rather than adding salt to your system. I have read here that some others recon their plants tasted salty after doing that. Whats the temp of your water?? Ich is less prevelent in warmer water so if you have a heater perhaps increase the temp to say 24c.

not a bad idea, if you caould set up like a hospital tank style arrangement, but then is the ich still in the water when they go back in to the main tank?

Be very careful about increasing temperature.

It works like this, ich is generally killed off at about 30C but the higher you raise the temperature the quicker ats life cycle, reproduction and infection rates are. Its a double edged sword. I wouldn't increase the temp unless you are going to dose with 3 to 5 PPT salt, in which case it will shorten the life cycle down while having something in the system that will kill them. Ich is only vulnerable (regardless of treatment chemical) in one of it 3 (or four?) stages, the free swimming stage between when they burst from the fish and are free swimming, until the time that they burow into another host (can be the same fish).

Ich is also VERY misdiagnosed. Although flashing is a definatly a symptom, it is also a symptom of MANY things. They flash becasue they burrowing parasites make them itchy

The tiny silver perch in my "creek water tank" has been flashing wuite a bit, but i'm not going to diagnose white spot until i see the white spots.

Having said all that, the beauty of salt as a treatment is that it doesn't really do any harm as long as you stay below the fish's tolerance. I posted a salinty/species calculator, i think its under the links section. look up barra, but they handle sea water, don't they?

With salt, MORE is better. To be technical, salt works by changing the osmotic pressures on a cell. fish are able to compensate for this, while many parasites, bacteria and fungus are not, or only very slowly. Hence what you want is a reasonably large STEP change. Ie from 0 to 3PPT (3000PPM). If you tank was at say 2ppt incresing it to 3ppt may not have much of an effect.

And yes, i have cured a whole aquarium tank whose inhabitants included scale less fish like clown loaches which are very vulnerable to ich, just by raising the temp to 29C and adding 3PPT salt for 2 weeks.


Steve

Thanks for that Steve. I have added the salt - 1.5kg after doing a 200L water change. Although, I have not seen an infestation of white spots, the fish are flashing and specifcially rubbing their heads/gills against the tank walls and the pump. Some seem to be getting quite agitated by it. I guess lets wait and see.

FEB 2007
3-4 months in from set up. To recep 1300L tank, Murray's grow bed, 2kg of salt, an external filter and 25 perch!

The 25 silver perch I bought are now between 4-6 inches and the 4 goldfish have all ballooned! They are doing very well.

The grow bed on one side is going great guns, the other since I planted a heap of tomatoes have pepper plants which are now yellowing, whereas the opposite side have heaps of peppers! Any ideas?

PH is quite low 6.3 (I have shells in the water and in the gravel bed) but it hasn't moved up for about 3 or so weeks now. And ammonia is in dangerous territory, but the low PH seems to counteract that. I have 1litre of zeolite in the canister filter, which seems to have minimal effect. I have been sitting at these readings for 3 or so weeks, without any obvious detriment to the fish. Just can't get the readings down.

I have no rain water for a water change or top up and with choloromine in tap water, I do not wish to add more ammonia to the tank.

So here are my photos:

Hi Marcus, I would get rid of the salt ASAP. I have had itch in my system and treated with salt, fish fine, plants sick as.....
Yellowing etc I would suggest is the salt. Silver beet is as tough as old boots so it will cop the salt ok, but Tomatos , cucumbers and capisum all react badly to salt I have found.
Glad the grow bed is good.
Murray

Marcus, check out the underside of the capsicum leaves to make sure there aren't any little mites. Mine look like that, on the underside they have a fine matting of web and heaps of little critters about the size of a full stop. Just one possibility, but the salt is definately detrimental as Murray said.

I think Marcus is looking for ideas regarding the ammonia as well. Marcus - exactly what are your readings for ammonia, nitrite and nitrate.

Also - approx how much do you feed the fish eash day?

Yeah, skipped that bit! All I can think of is the bacteria are suffering at the low ph. Also Marcus, are the shell grit in your growbeds either under the flow of water or deep enough in the gravel that it gets a good time in contact with the water. I put my shell grit in lines under my irrigation pipes and it works a treat