How much water change for a large planted tank?

I recently setup this planted tank, inspired by the humongous 1600-gallon planted tank which Tom setup for a client. Mine is obviously smaller, with less variety of plants. I also have a 180-gallon refugium underneath.


I recently added automatic water change, which drains 10 gallon every 4 hours --> 60 gallons a day, 420 a week. Is this enough water change for my setup? Should I increase the interval between drainage?


Thanks

 

The refugium is a habit from my reef tank days. It is additional insurance, and for me to grow out some of the plants initially.


I was so inspired by Tom's 1600-gallon tank that I knew I want to do something similar. But planted tank takes a lot of pruning and maintenance during the first 6 months, so I designed the tank to be 32" high instead of 48". Looking back, a depth of 48" would be better, but mine is only 40" deep. I only have space for 10-foot long tank.


I will try to post some setup pictures for the tank once I know how to host these pictures.

 

Thank you so much, Tom, for your great suggestions. Reading your previous posts, I agree with your advice against having a wet-dry sump/filter for a planted tank. For my refugium/sump, I tried to minimize the CO2 degassing effect by: 1. sealing off the overflow box; 2. extending the drainage tube deep into the sock filters; 3. draining some water from the sock filter section thru a few side holes to the refugium planted area. I will look into modifying that section to further minimize CO2 loss through degassing.


My wife loves those stem plants (Ammania Gracilis). Beside Blyxa as an alternative, how about more Crinum Calamitratrum or Alternanthera reineckii (for color) or a mix of those? (Similar to what I did on the right corner).


I already have more than 100 cherry shrimps in the refugium. My plan was to move them into the big tanks once they are bigger. I will look into adding another 100 cherry shrimps. My elephant nose fish needs live food too.


With my automatic water change, the drainage is currently via gravity, not by pump. The volume I can drain is somewhat limited by the refugium return pump section. After reading your advice, I switched to 15 gallon every 6 hours.


It definitely helps to get such good suggestion from an expert.

 

Water parameters: I have never tested the water since I started the tank. At the beginning, I was almost tempted to test them when some blue green algae showed up at the bottom. But they went away after I cranked up the CO2 and added a little dosing of Potassium Nitrate every day for a week.


For fertilizers: Every week, I add a few scoops of Ca:Mg Sulfate mix at 4:1 ratio. One scoop of Miller powder for essential elements and Iron. Every 2-3 weeks, I add a few scoops of KSO4 to replace K loss. I never use EI or any consistent dosing method. I bought a doser but too lazy to refill the solution containers on a regular basis. Tom is right to suggest water change; I have an automatic water change setup, plus a 40% water change every 2 weeks. I am sure that I will start testing more regularly when I start running into more problems in the future.

 

Crinum Calamistratum.