I am considering adding a number of floating rafts to my fish tank. For those of you who have not seen my other posts, my fish tank is an in-ground swimming pool. Because the pool has not been chlorinated for some time now, floating algae has made the water all but opaque.This algae is growing faster than my sand filter can remove it.
What I am thinking of is adding several floating styrofoam rafts to both grow something absorbing the nitrates and to shade the water so the algae is at least somewhat depressed. Now I have a couple questions here.
I will be adding catfish in a few weeks. I know catfish are opportunistic feeders, but do not think they actively eat plants. True?
Also, my plant selection will be important. Since the rafts will be free-floating, the plants will have no support. Taller plants will be out of the question. I need suggestions for lower stature plants that might do well. During the cooler months, lettuces, kales and the like would be suitable, but what might I use for the hotter months?
I bought some bare-root strawberry plants at one of the big box stores and out of 50 none grew. Not sure if all "drowned", or they were duds in the first place. Unfortunately, I did not think to test a few in one of my dirt beds to see how they did there.
I see from your post that you already have GB's installed. If your FT is open and exposed to light, with algae build up, why not simply shade it with shadecloth. You can make a basic PVC frame and use tie-straps to fix it(see pics on my page if you need an example). Making a raft out of the FT can pose quite a few problems for you further down the road.
Harold, my fish tank is a swimming pool... it is over 30X 18 feet, so a suspended cover is not possible.
David, tomato cages would still tip over in a free-floating raft out i the middle of the pool. I have already rigged supports for growing taller plants in my growbeds, but was looking for something with a low profile in the pool itself.
Then I realized the fallacy of my original plan anyway-- Any attempt to cover the pool surface with enough rafts to be effective in even a minimal effect on algae growth would decrease oxygen absorption into the water. Right now, with a minimal animal load in the water that might not be bad, but in a few weeks I will be adding 300 catfish fingerlings.
Pat, when I was a little kid I had a cousin who had one of those big ass almost olympic sized swimming pool jobbies...They had this screen-type debris cover. It was basically a big roll that ran on two rails which ran length-wise along the sides of the pool. You could rig something similar with a roll of shade clothe. Just a metal frame on either side upon which to roll and un-roll your shade clothe..? Forgo the metal rails altogether and get a 20+ foot piece of metal pipe (or wooden 'log') and roll your shade clothe up around along the concrete sides. It would probably take two people to operate (my cousins had a hand crank and mechanism which pulled a system of wire ropes blablabla...so it took just one kid rotating a hand crank to operate)...
Maybe a couple grommets sewn in here and there where you could fasten the shade clothe down so winds don't mess it up...Just an idea...
I feel i didn't get the idea across clearly, sorry, my fault. I meant a floating PVC frame covered with shade net. At some point in the frame a cutout section to allow feeding, etc. The frame will be light and fairly inexpensive keep out debris, pest, and even act as kid safety protection etc.
Vlad's suggestion is probably the cheapest and easiest way to shade the pool. You can also purchase a dozen beach balls to help float the cover above the pool surface. You do have your own set of challenges with your set up. Lucky you.
BTW Kale is very tough and grows all Summer here very well and man that Portuguese Kale Soup is to die for.
My pond was/is also a swimming pool. Water Hyacinth in the summer is a great plant to have to filter and shade. I stack bread racks in the shallow end and attach bare rooted plants. Sweet Flag is currently my fav because it is evergreen. I use a burlap cloth to cover the plastic racks and attach moss to make it look more natural. I would use something other than Styrofoam. It breaks down and you have little bits everywhere! Not good for fish! Are there any fish other than catfish? The cats will be less likely to be interested in your plants if there are baitfish around to munch on. Good Luck.
Pat, I've seen several discussions on algae problems on this and other blogs. I don't understand why folks can't just do what I did and put in algae eating fish. I put 1 into my IBC and he turned it into clear water from an algae covered container. Started noticing the difference right away. In your pool you just need more of them and while they aren't edible they will continue to do there job right on so you don't have to contend with floating structures. Probably wouldn't cost any more for these fish than to build a cover.