Sump refiltering and the use of algae.

Cut a piece of glass the size as the sumps first chamber so it can slide down into it, with a slight amount of room around it.
Drill three large holes or more if they can fit in the glass just allowing small gaps between each hole.
Sit your piece of glass top facing down on some paper; draw a line all around glass piece on the paper.
Lift the glass and run a bead of acidic cure silicon on that line on the paper.
Flatten the uncured silicon with a paint scraper or what ever to make the silicon 1 to 2 mill thick and let it cure for a few hours.
Take the glass and wash it with warm water with a small stiff brush, except for some colour from the paper, if words were on it like newspaper, the paper is now gone from the silicon.
Cut around the silicon where it over laps the glass leaving 3 to 5 mill of silicon past the edge around all of the glass piece, this is now the seal for when you slide the glass back into the sump.
Don’t slide this into position until the silicon as had a day to fully cure.

Cut a strip of glass 20 mill wide and then cut small sections of this, say 3 mill long and silicon them to the base of this piece of glass, these keep it up off the glass floor to attain a gap under this.
Cut some conduit lengths just 30 mill or so long that are slightly to big for the holes in the glass that you have drilled and heat one end of each one and push each into its hole and flair the under side end that will be under this piece of glass with a small funnel or drink bottle end as it cools.
Once you have finished them, cut one 6 inch piece of the same sized conduit and smooth the end with sand paper, some lengths of the same sized conduit and heat one end of each at a time, use the 6 inch piece and force in the smoothed end of this into the heated ends of each piece of conduit and wriggle the 6 inch piece while you run the tap over the one that was heated.
They will now slide over the ones set into the holes in the glass.
Then you get sections of conduit the next size down, compared to the pieces set into the holes and cut them to the height you want you water to remain at and sit them in the conduits set into the holes.

Now perforate the external sections of conduit pipes that will hose your filter wool-wadding that will slide over the ones in the glass, I use an angle grinder to make them full of slots.
Have these open at the top and 20 mill higher then the internal sections of conduit.
Now cover them with filter wool but not the opening at the top and you can take them out and clean these pre filters easily any time you want to.
I clean mine each day and put them through the washing machine after the fourth or fifth rinse off and put fresh ones on when I go away so it takes many days to block them.
The floor area catches particles and life that makes it out of the tank as well and these pre filters stop everything from ruining your sumps cleanliness!
If the sections of conduit that you put into the glass are cut just above where the water line is and when you turn off your return pump, when you clean these pre filters you are actually using and you have made and put in place settling prefilters and you are now so far ahead of other reefers with how well a sump can operate and it will remain clean, always!

Your algae for importing nutrients, make a raised floor of egg crate 30 mill off the glass floor and do not use a substrate.
Put pieces of dead rock-base rock of 15 to 40 mill sized pieces for the algae’s attachments to hang onto, algae does not have roots, they are attachments, they do not operate like plants roots!
This base rock should be made at around 4 to 6 inches deep so it will account for some nitrate reduction and more!
Finish the base rock 6 inches from your water height to get the best growth out of your algae.