just added fish and ammonia is on the rise

[Randy Paul]

Hi all

I have a newbie question.

I have just added fish to my system.  I had done a fishless cycle and the system is about 10 weeks old. I have a lot of plants that are doing great, been adding sea weed extract for added nutrients.   I have had the fish in for about 10 days and my ammonia levels seem to be rising.  It is at about 1 PPM .  and cannot figure out why.  During the fishless cycle I could add ammonia in to a rate of 1-2 PPM and in 24 hrs it would be down to zero. So I assumed that the system was cycled.  Could I be feeding the fish to much ? 

 

System details

Ammonia: 1.0

Nitrite: 0.0

Nitrate: 20-30 ppm

Ph: 7.6

Fish Tank size: 600 gallons

 3 Grow Beds  8'x3.5'x12"

Age: 10 weeks

25 bluegill ~ 3-4”  20 catfish 4-6”

 

  

[George]

It wouldn't hurt the fish at all not to feed them for a day and that would be better than killing them.  Your water tests look pretty good other than the high ammonia.  I'd skip a day.  Since the early period my ammonia has never been higher than .25.  That sounds like a nice system you've started and you could certainly add some grow beds later.  I'd rather skip feeding than worry about it.

[TCLynx]

What are you feeding them?

Those grow beds?  Are they Media beds or raft beds?

What is your pumping schedule?  Is it a siphon flood and drain system or timed flood and drain?

I'd say skip feeding for a day and run the pump constant for several hours if it is a timed flood and drain system.  And check to make sure your pH test is functioning properly because a sudden rise in ammonia in a previously cycled system is often due to a sudden drop in pH.

You may simply be feeding them too much.  Is there any uneaten feed in the tank?  Any fish poo collecting?  Or anything dead that might be spiking your ammonia?

[Randy Paul]

TCLynx said:

What are you feeding them?

Those grow beds?  Are they Media beds or raft beds?

What is your pumping schedule?  Is it a siphon flood and drain system or timed flood and drain?

I'd say skip feeding for a day and run the pump constant for several hours if it is a timed flood and drain system.  And check to make sure your pH test is functioning properly because a sudden rise in ammonia in a previously cycled system is often due to a sudden drop in pH.

You may simply be feeding them too much.  Is there any uneaten feed in the tank?  Any fish poo collecting?  Or anything dead that might be spiking your ammonia?

 

I am feeding them high protein pellets .

The beds are Media filled

Using a bell siphon with continuous  pumping

 Ph is 7.6 and has been at a constant.  I use hard well water to top off the system till I can get some rain barrels set up.

I did not feed them yesterday and the ammonia is down to 0.25 this morning,  so I think I was just over feeding them

Thx all

[TCLynx]

Yea, high protein feed can push a new bio-filter to it's limits if you over feed.  Generally if you see the ammonia rise, you should back off the feed a little till it drops back down and slowly increase the feed until the bio-filter can handle as much as you need to be feeding.

Sometimes extra aeration can help too.

[Randy Paul]

Update:

The Ammonia level is down to 0 , started to feed fish again , but not as much .  One other item that may have been adding to the problem.  I have a large filte in the sump between the return from the fish tank and the pump.  It was full of un eaten food and poo.   I did not think in 10 days it would be so full.  But cleaned that and will keep a close eye on it from now on.

Thx for all the help

 

[TCLynx]

Filter foam is not really recommended on pumps for aquaponics.  You need a mesh or large screen to make sure debris can't get into the pump and mess it up but you actually want the fish poo and uneaten feed to go to your grow beds.  That stuff clogging up the filter foam will just restrict your flow and cause you problems.

I only use such foam when I have small fry in a tank and I need to keep them from going for pump rides into the grow beds.