discusdean said:
cheers guys,
ceg the tank is much better after your advice with regards the algae and the growth is increasing what lighting would you suggest upgrading to i have 2x 52w t5 and 1x 32w t8 at the minute
have noticed the Ph swing is worse around Sunday Monday according to my computer so am associating this with water change ,what do you guys do to your water prior to a change maybe this is where the answer lies.
many thanks
dean
Hi dean,
You are absolutely correct in that the pH swing is greater on water change day since most peoples tap water is neutral to slightly alkaline. Like Ed says, if you are using RO water just add whatever GH corrections you need to, and then add the water to the tank. I don't use RO so I just stick a garden hose in the tank and turn on the tap. I'm not sure what other "answer" is necessary. I think I measured my pH a couple of months ago last I recall. It was somewhere around 6. pH or it's swings are simply not an issue.
The amount of light you add is optional. We'd have to know the tank size to offer a suggestion, but I always liken adding more light to increasing your car's speed on the motorway. From what I recall I believe you indicated having a 500 liter tank (125 USG). More light means more risk of algae. 2.5-3 watts per USG of T5 is enough to grow just about any plant, but if you don't add enough CO2 and/nutrients you can easily turn your tank into an algae farm so I would add more light carefully and slowly. 125USG should have not more than about 375 watts T5 with reflectors. If you have 100 watts T5 and 100 watts of T8 then I count that as roughly 150 watts T5 (I reckon T8 is about 1/2 as intense as T5 - not a super accurate calculation, just roughly speaking.)
If you go to 375 watts T5 level of lighting you then need to upgrade your filtration. A good target would be to have a filtration throughput rating of 5000 liters per hour. A tank that size lit with that amount of light would easily consume 10 kg of CO2 per month. If you wanted to use less CO2 then you would consume more Excel.
Water change schedule would also have to be upgraded to not less than 250 liters per week.
As you can see, this is like doing 100mph on the motorway. Everything gets accelerated, risk and reward. If you want to go for it then first try adding another 100 watts T5 and see how it goes for a couple months. Remember to increase all the other items proportionally though.
These are not absolute numbers, just ballpark figures to get your head wrapped around the ramifications of increased lighting.
Cheers,