Phyto Auto Dosing - Continuous vs Batch

[niccumec]

Pro’s and Con’s of continuous vs batch dosing of phytoplankton???
1. Continuous: 4ml every 30 minutes, or 192 ml per day - Skimmer and UV on 20/7
2. Batch: 100 ml in batches 2x per day - with skimmer and UV off for 2 hrs after batch
3. Both: 4ml every hour and 2x 50 per day (with UV & Skimmer off after batch)

Also day versus night dosing - does it really matter.

 

[DanyL]

I had a big plan to setup a continue phyto reactor that I eventuat ended up scratching.

Outside of the problem of keeping it sterile for long periods of time to prevent the culture from crashing, there is also a bigger problem - trace elements.

Usually when you grow phyto you add the fertilizer, give it a week or so to grow and than harvest. During this week the fertilizer is almost fully consumed, and still many reefers report an increase in various traces in the tank accumulating after a while. For a continues culture to work you will have to supplement it daily with a small dose of fertilizer, which will most defiantly make it into your tank in much higher concentrations, destabilizing your system and causing harm to your corals.

There are also other easier problems, such as evaporation for example, which can be mitigated by making the fresh saltwater that you will need to add to compensate for the dosed amount with lower salinity.

That’s just a few pain points I’ve gone through trying to design my own system before I figured that it wouldn’t justify the amount of time and effort required to make it work.

 

[niccumec]

I guess I should differentiate auto dosing phyto from continuous culturing of phyto. I still manually harvest the phyto every week and start a new culture. 1000ml goes to my Tisbe pod vessel, 250ml to fridge for backup culture, 250ml from previous weeks’ backup from fridge to start new culture (I always have 2 different 250 ml backup cultures in the fridge, using the oldest one to restart the new culture) - leaving ~1400ml to auto dose to tank, or 200 ml per day.

The 1400ml for tank stays in Poseidon container (or rather the bag within the container) with air tube to keep phyto suspended for the “dosing week”. This has worked quite well over that past couple of months. The 1400ml phyto to be dosed stays nice a green throughout the dosing week without the need of refrigeration emptying over the 7 days while new culture matures.

My question is more on the frequent doses throughout the day versus larger more infrequent batch doses and the real effect that UV and skimmer may have on the phyto.

 

[Harpo]

I have also been considering this. If I had multiple sealed containers each gravity feeding into the next. The input would be new salt water, F2 fertilizer, light & air. The output would be phyto into my tank. My big question is how many vessels and what is the feed rate of the new salt water to ensure the F2 is used up before being fed into my tank

 

[Pistondog]

My continuous phyto dosing.
1. Batch 2 or 3, 3 liter cultures of phyto weekly, staggered
2. When culture is done, empty into 10 gallon reservoir for awcs, with a pinch of f2. Top off reservoir with new salt water as required.
3. Reservoir is lit 6 hours per day and agitated continuously.

The idea is to try to keep reservoir phyto viable as long as possible. Dosing dead phyto is also a valid food source.

 

[Harpo]

Thanks, why only 6 hours of light?

 

[Pistondog]

Thanks, why only 6 hours of light?

Just enough to keep phyto alive, my guess.

 

[Randy Holmes-Farley Verified Community Expert]

I autodose phyto once a day (at night) and shut off my skimmer for about 2 h each time.

 

[Harpo]

I thought about doing that, but I was worried about phyto in the tubes for 23 hours. I'm dosing .1ml/min