Backyard Aquaponics
A place to discuss aquaponics

Your options for the pH go something like this.

1. Leave it and it will come down as the nitrification cycle takes off.

2. Adjust the pH using an acid. Hydrochloric aka muriatic acid works well for this. You can either adjust the top off water each time you add water so that the change is gradual or you can remove some of the system water adjust the pH and then add it back to the system (again the intent is to get a gradual change). Another option is to remove some system water of known volume and adjust it to the desired pH with a known amount of acid (let it sit a couple of hours and check the pH again before assuming you got it right - adjust again if necessary). Once you know the amount needed for the sample you can figure the amount needed for the system based on the volume in the system.

You don't want to change the pH more than 0.4 pH units at one time to prevent stress to the fish. Your eventual target is around 6.8 to 7.2. If you change the pH too fast the fish will likely live but it's not a good thing.

It's 9 a.m. on the Wednesday so the fish have certainly survived from the algae treatment. The water is nice and clear however the fish are still not interested in eating they are swimming in circles just underneath the surface appear to be healthy why would they not be eating?

Sounds like they are adjusting to the new conditions, I don't think you should be too concerned about it at this point. Keep in mind that with the algae gone the fish may not feel as safe because visibility is higher. Fish have low energy requirements and can go for weeks without eating. They may see you and stay below the surface so walking away might encourage them to eat and feeding them at a different time when the lighting is different sometimes helps as well.

If the water temp is too high or too low they won't eat or will eat much less so that's another consideration. Depending on the type of fish you have, the temp that they stop eating will differ. Usually below around 50 to 55F most fish will stop eating or eat very little and you should stop or at least reduce feeding. Tilapia will probably stop at a higher temp because they like warm water.

Do keep an eye on your water parameters since the dead algae can result in an ammonia spike as it breaks down.

Well message to everyone doing aquaponics DO NOT use chemicals to treat algae or anything else. It WILL KILL your fish. After treating as detailed as above I have lost all my fish. Sure the algae went but that is little constellation if you have nothing in tank.

So I have to remove water, clean tanks out and get new fish after water cycles. As trout need to be harvested by November in this part of the world I will have to source larger ones (Summer and hot weather means they don't survive beyond November

I am devastated. But it is my fault. So carefull planning is essential if you are to have a good setup

Sorry about the fish Ozzyrod, I wasn't expecting such a rapid death after they lived for that long after the treatment .

Most algie is caused by to much sunlight

phosphorous is also a key limiting factor. Its presence causes algal blooms

Try some different fish.I have some koi and I can put as much algae in the tank as I like and they will clean it up in no time .I have six little redfin in another tank and they have cleaned the algae out of that now .It is in full sun. Evidently the real small redfin live on algae for a while .You may not want to eat the koi but they poo in the water the same as the rest do. I have seen them eating algae off the side of the tank.