Black Diamond Blasting Sand and an undergravel filter

[wayneb64]

I have been in a long battle trying to control algae in my tank and the latest idea was based on reading that you want to fertilize your plants via the substrate not the water column. This means the plants get the nutrients and not the algae.

I have read a few things hear and there and it seems like Black Diamond Blasting Sand (Medium) is the best solution and it's cost effective. My dilemma is that I have an undergravel filter (plus a cheap OTT filter) which I want to keep but I am afraid the sand is just going to clog up and/or just pass through the undergravel filter slots. I don't have the sand yet as I am still doing research so I am not sure of the size range of the particles for medium.

I know I need to rinse it very well before use and I was thinking of sifting out all the smaller particles hoping that the larger ones would not pass through the UG filter. My curent gravel is pretty course and only the smallest do pass through.

Is there a better substrate to use with my UG filter that is inert and good for plant roots? I think my current gravel is just a bit to large to use with fertilizer tabs.

Thanks for any help.

 

[ZxC]

I would suggest the opposite. Fertilize the water column and not the substrate.

Fertilizing the water column is not really a sole source of algae... A proper fertilizer dosing schedule should ensure your plants are getting what they need in proper proportions, and will limit algae's changes of taking over.

Thrive, Easy-Green or DIY such as EI or PPS-Pro are good water column fertilizers to research into.

If you are having algae issues, there are many other, less drastic ways, to compete against it without a substrate change.

 

[wayneb64]

I have Thrive but stopped using it because it contains Nitrates so I was getting to much of them in order to get the rest of what's in there. Seachem Flourish is what I am using now, it's just the micro nutrients so maybe not the best but I am not sure how to add the other macro nutrients.

I think I have exhausted all the other algae control techniques to little success. I now have fast growing plants like Wisteria and Hornwort. which btw I have been removing huge amounts two weeks in a row now as it grows so fast and yet still the algae is unphased. I have CO2 injection and a power head, plants and fish seem very happy but so does the algae.

Having read a bit more since my first post I see root tabs would be pointless with my UG filter. Their nutrients would just end up in the water column.

My change this week is dimming down my lighting system to see how that affects the algae.

 

[ZxC]

Reduce lighting by both dimming them and leaving them on for 5-6 hours a day max.
Increase both your water change frequency and amount changed.
Clean out your filter(s) with every water change.
Vacuum the substrate during each water change.
Ensure your pH is dropping at least a full 1.0 from using CO2. To do this, measure pH before the CO2 is on for the day, and then measure 1-2 hours after it has been on. Note the drop in pH. If it is less than 1.0, slowly work up to that over the course of a week - 2 weeks.
Use Excel / Metricide 14 at a high rate (the "after water change" on the Excel bottle or equivalent Met14) daily.
Spot treat bad areas with H2O2 and/or Excel/Met14.
Manual remove as much as possible.

Your NO3 levels should not be an issue if you are following the directions on the bottle of Thrive unless you are drastically over stocked, haven't cleaned out the substrate / filters in a long time, or have NO3 in your source water.

Flourish Comprehensive is fine, I suggest coupling it with Flourish Trace as well.

To get the other macro nutrients, you can dose KH2PO4 and K2SO4 for Phosphate and Potassium.

https://rotalabutterfly.com/nutrient-calculator.php is a nutrient dosing calculator to help you determine how much to dose and what you would get per dose.

 

[wayneb64]

I have Excel but stopped using it after I got the CO2 injection going. Is that the same thing as Met14? Not familiar with that. Also not sure what you mean by spot treating with this.

I am probably overstocked, 10 glow tetras some pretty big and two clown loaches about 2-3 inches long. My tank is a 30 long with about 5 gallons of rock and gravel.

My nitrate levels are about 20 ppm and my phosphates are undetectable.

I read something recently suggesting the only level that matters as far as nutrients is the minimum level of one of them. If there is to much of all of them then the plants won't out compete the algae. Not even sure it's all algae, I have green stuff, brown stuff, and black stuff that I clean every week.

 

[ZxC]

Any pictures?

The stronger the light, the faster the plants can photosynthesis meaning the more nutrients they need to feed growth...

I dose 15ppm on top of whatever my livestock gives me, NO2 levels hover around 20-30ppm and plant uptake = livestock production.

0 PO4 is not good, plants need PO4 in large quantities.

Algae and plants don't "compete" for nutrients. Algae spores need ammonia to germinate, ammonia among other "sugars" are produced with un-healthy, hungry plants. That's why algae takes hold when plant growth is hindered. Feed the plants, they will grow instead of struggle meaning no food for algae spores.

 

[wayneb64]

I see the link to how to calculate how much of something to add to get so many ppms but where can I see what 'good' levels are for these like say potassium or phosphate?

 

[ZxC]

I see the link to how to calculate how much of something to add to get so many ppms but where can I see what 'good' levels are for these like say potassium or phosphate?

That's up for you to decide.