Backyard Aquaponics
A place to discuss aquaponics

hey stucco.. didn't you use paraffin wax? or was that someone else....

Keith

It was stucco. I looked into that and I just dont think it will stay solid in the texas heat. according to sliki it's melting point is 99 F. And the texas sun is going to make some surfaces hotter than that. The water temps could get into the mid 90's and that's if i can grow enough hops to shade it.


brian

What do you mean if? I need you to grow lots of hops, so I can home brew vicariously through you!

It's just going to be late this year and even hops have a hard time growing in 100 degree heat. Next year i doubt it will be a problem and the third year it will finally have the roots established going into the season.


brian

Three options for coating the tank that you might not have thought of -

1) Thoroseal. White. Cement based, polymer modified
2) Gripset 51. Dries black. Solvent-free modified bitumen.
3) Gripset 2P. Dries light grey. Latex cement based


All are approved for the storage of drinking water. I like Thoroseal. It's cheap and widely available. And it can be added to sand and cement to make a finishing layer to smooth the surface while waterproofing.

Curing:
1) Thoroseal cures 7-10 days. Then wash with salt brine. Cure 1 day. Rinse
2) Gripset 51 is water based and needs a 10 day cure before leak testing and21 day cure before permanent submersion.
3) Gripset 2P has a 72hr wait before leak testing, and a 21 day cure time

I make my tanks 1.5" thick and seal the inside with epoxy to protect the armature from moisture. the outsides i generally use an acrylic coating ie; dryvit or sto finishing systems. if your interested in beefing up what you have you can use a bonding agent (i prefer acrylic) to brush or roll on and then reapply more coats using a drywall hopper gun.

smatthew,
thanks for the input. I should be able to get a 50lb bag of theroseal at ace for about $40 and that should be enough for 2 coats on the inside or outside so that's more like it. Since it's cement based, I assume the main goal here is to protect the seal frame on the inside?


stucco,
That's good to know. Your walls on your grow beds looked very thick and it seemed like a crazy thickness once i started mixing cement at 1.5 cu ft at a time... my walls are probably 2" thick on average but i cant say it's uniform. I'll keep this in mind when i finally get to start the grow bed.

brian

I made this youtube video of my fish and aquaponics system for a thread on another forum but thought people m ight have interest in it. The main focus is using fish native to north texas.





http://www.youtube.com/watch?v=AhF1e-Nr ... e=youtu.be

brian

I had a loss today. I wish i had done a closer picture.

This is an LMB that appears to have choked on a small redear sunfish. One month ago the LMB and redear were all about the same size, (2-2.5" long).

This was one of my largest/fastest growing LMb but there are others of comparable size. I lost a couple more redear recently that were not eaten but seemed to have trauma/bruising on their bellies. I am going to have to drain this tank and separate the red ears from the LMB asap to keep from losing more feed trained redear and hopefully stop losing LMB?

overall the LMB growth rate seems every bit as fast as any tilapia if not more vigorous.

I would go with thoroseal. Proven reliability in cisterns. On the outside maybe EFIS coating used for colored stucco finish. I never have luck with epoxy based coatings exposed to sun and freeze/thaw cycles. I have done quite a few outdoor kitchens with the EFIS coating and it lasts. The concrete counter tops I build always give me problems with acrylic or epoxy based coatings.

Update,

Noone has basements here in texas so i couldnt find the theroseal in a store. I had to buy it from ace hardware online and get them to to ship it to the store for free. As far as i can tell it's unavailable from home depot and lowes to ship to here.

Yesterday i picked up two 35 gallon pales of white super theroseal along with 1 gallon of the acryl 60 cement additive which the directions say to use. I should have enough to do the required two coats on the inside and i will probably have enough left over to do 1 coat on the outside, we will see.

While i was waiting for the theroseal i treated the water with a gallon of muratic acid. It stained the cement a rust color and lowered the PH. i drained the tank and refilled it with water from my main system (ph 8.2) and it still rose to over 9 (off the high ph scale) so it's still leeching and leaching more than i can manage ph wise. I did put some minnows and a couple of tilpia fry in the tank. Algae was already getting started. All seemed to live and grow well until i took them out today.. so the fish and green algae didnt seem to mind too much.


Since i got the theroseal i have drained the tank again and i now have to clean it and prep it for the theroseal. There is some algae one the walls and floor and the cement itself seems to have a thin brittle layer. I hope that i didnt ruin the cement with the acid. Anyway. I'll get some pictures asap and document the the application process. I invested in a cheap 1.5 gallon gravity fed texture spray gun at harbor fright so i am hoping the application turns out to be easy.

Still havent begun work on my ferro grow bed. A lot of real life is getting in the way of the progress both time and financial wise.. not to mention it has gotten way too hot to work outside for long periods of time... but anyway , this was intended to be a long term project.


brian

Im enjoying your updates Brian.

I have a serious interest in ferrocement so am hoping to learn from your thread.

A question.. Do you think it may have been cheaper to purchase a poly tank? Or for you, was it a visual thing?

Cheers

OK,

well, i cleaned up the rusty color caused by the muratic acid. It was just a thin layer of dust that was red colored. Most of it came off with a brush and then i went over it with a vacuum to pick up any other loose particles.

Theroseal report.

The jury is still out. It was easy to mix. I mixed a 35 lb pale of the super theroseal with 2 quarts of acryl60 and about a gallon of water.

It 100 degree days in texas right now and the sun is harsh. I intentionally waited til only about an hour of sunlight left and started moistening the cement as per the instructions to avoid "flash setting" which i didnt seem to avoid. The cement was still very hot from the long hot day.

I used a texture blower thingy i got for 25$ from harbor freight and it seemed to do a good job off spreading out the theroseal. But this was a 1 man job and i put on the whole coat and then tried to rub it in with a brush but it was already turned into as ticky clay/playdough texture and i wasnt able to work it in very well in most places.

The directions say to wait 24 hours to apply the second coat but i checked it in the morning and it was dry to the touch and the cement was a lot cooler so i decided to put the second coat on this morning. It went about the same. As i am writing this i just remember that i did not wet the surface before spraying so that may have been why i didnt have any better results today. The second coat is supposed to only take half the product but i used another 35 gallon pale with 2 quarts of acryl60 and about a gallon of water. Againt it didnt spread very well after i sprayed on the product. It would probably have been a good job fr 2 people 1 spraying and one brushing it in.

I am still hopeful that it will be enough covering to be functional. There's some large cracks from my uneven ferro work that may not be sealed, however.

There's also a patching product by the same manufacturer call water plug that may be best for filling in these cracks

The two pales of theroseal and the 1 gallon of acryl 60 cost ~$120. The surface area of the 800 gallon tank is about 140 square feet, give or take.

It's almost been a week since i did the super theroseal application. I will rinse the walls and then start filling the tank this weekend.


In the mean time i added a dual SLO.